SAN FRANCISCO – Brandt Snedeker has withdrawn from the U.S. Open due to a rib injury and will be replaced by amateur Jordan Spieth, who recently completed his freshman year at Texas.

Spieth competed in sectional qualifying at Lakeside Country Club in Houston, shooting matching rounds of 70 to earn the first alternate spot. The two-time U.S. Junior champ will tee off at No. 9 at 4:14 p.m. ET on Thursday with reigning FedExCup champ Bill Haas and Nick Watney.

The injury also caused Snedeker to withdraw prior to the third round of the Memorial Tournament. 

A final-round 75 wasn’t the finish Jordan Spieth was hoping for, but it’s all part of the learning experience for the 18-year-old University of Texas freshman. “I gained a lot of confidence from it,” Spieth said. “It didn't end the right way but it was a great week overall.” At one point in the third round, Spieth climbed as high as the top 5 on the leaderboard at TPC San Antonio before a bogey-double bogey finish derailed him as he closed in 40 to shoot 72. This was the second PGA TOUR event of the year for Spieth, who earlier this season missed the cut at the Northern Trust Open after rounds of 76 and 71. Last year, he tied for 32nd in the HP Byron Nelson Championship and in 2010 tied for 16th there before missing the cut at the FedEx St. Jude Classic the following week. For now, though, Spieth will head back to Texas, where he’ll focus on school and the Longhrons’ post-season, and Big 12 and National Championship race. “I'm glad to be back and joining the team for that and then can't wait for summer,” he said. “This summer should be filled with quite a few tournaments.”

By Fred Albers, PGATOUR.COM Correspondent

Shut the face: Ben Curtis headed right to the driving range following his third round. He hit just eight fairways on Saturday and thought he knew the reason why -- he was shutting the club face. He spent time working on his grip and swing plane on the range and was encouraged by the perfect drive he hit on the 18th.

Slow Start: The combination of high winds and difficult greens made for a brutal pace of play in the third round. The course backed up from the very first tee. It took one hour to play the par-4 opening hole and the par-5 second. The last two groups were a combined 17 over for the opening nine. Ben Curtis teed off at 11:45 a.m. and finished at 5:36 p.m. local time. That's 5 hours, 51 minutes for a round of golf.

Wounded Warrior: Specialist Matthew Spang is part of the Wounded Warrior program and spent the day following Matt Kuchar in a wheelchair. Spang is a double amputee who lost both his legs while serving in Afghanistan. Kuchar rewarded him with autographed golf balls and gloves following the round and proudly posed for pictures, too.

The Question Mark: John Huh is known as the "question mark" for his unique last name but answered any questions about his determination this week. Huh played his first eight holes in 9 over on Thursday, but since then he is 13 under. It would have been easy fro him to withdraw after the opening 18 holes or even walk off at the turn. Huh turned lemons into lemonade and could win his second PGA TOUR event on Sunday.

Longhorns: Jordan Spieth let a good round slip away over his final seven holes. He was 5 under on the round but finished at even for the day after a double bogey on his final hole. The University of Texas freshman played with Texas alum Harrison Frazar, who also shot even par. They left the final hole, walking together, with Frazar quietly giving encouragement to Spieth.

Windy Day: Greg Chalmers proudly proclaimed he grew up in, "the third windiest city in the world." He's from Sydney, Australia, and was happy to see it blowing on Saturday. Chalmers managed to hit 10 greens and took just 25 putts. He rode the wind to a 3-under 69 and is tied for sixth place. Chalmers is hoping for even windier conditions in the final round. There is an expression on TOUR, "when the wind blows, the Aussies move up the leaderboard."

GIR: Why is Ben Curtis leading this golf tournament? Because he is hitting greens. Curtis has found a tournament best 38 of 54 greens in regulation and also leads in strokes gained-putting. That's a strong combination. If Curtis continues that on Sunday, he'll collect his fourth career win.

It certainly won't be like playing - and contending -- in his hometown of Dallas at the HP Byron Nelson Championship the last two years. But Jordan Spieth should still have a comfort zone this week as he plays in the Valero Texas Open for the first time.

After all, he's in the Longhorn State and the Texas freshman is only 90 minutes from Austin where he now lives. "It will feel like I'm at home, which will be good," Spieth said.

Spieth has adapted well to college life, too. The 18-year-old has helped the Longhorns win seven tournaments this year. Spieth schedules all his classes in the morning so he has the entire afternoon to practice and the No. 1 collegian in the country is seeing the benefits in his game.

"Really, just all around, just everything kind of been a little more consistent," Spieth said. "I've hit balls and putts and chips. Everything is just really more refined. I wouldn't say one area in specific is really just grown. More of everything, kind of the tightening up to how it needs to be."

Spieth is playing in his fifth career PGA TOUR event this week, and his second of the season. He tied for 16th and 32nd in Dallas but has missed the cut in the other two, most recently earlier this year at the Northern Trust Open. His goals are set on a PGA TOUR card, so these opportunities are invaluable.

"In all these TOUR events not only am I just measuring my own game against them but I'm trying to learn stuff from them," Spieth said. "They're all out here, PGA TOUR members for a reason. I'm trying to be where they are.  Obviously, I'm a lot younger than they are but, you know, I'm learning from them and I'm also able to compare my game and ... I've been in contention before, couple years at the Byron and couple times where I've struggled.
   
"So those were humbling experiences. So now I learn from those and I feel like I can compete with these guys, I really do, and that's not a reason for me staying amateur, whatnot. I mean there's tons of factors. But, you know, I'm confident in how I can match up against them."

Spieth feels TPC San Antonio suits his game, too. He came down and played a practice round a couple of weeks ago and feels the premium on hitting fairways plays to one of his strengths.

"I don't really know how other people feel but I expect myself to play well coming from playing a lot of really difficult courses already this year in the college ... and also playing the Northern Trust,” Spieth said.

"I have high expectations for myself this week and I know ... you're going to make bogeys out here and it's all about patience, but I feel like having played a few tournaments before, PGA (TOUR) events leading up to this, it's going to be a big help in how I settle in to start and kind of take control of my game in this tournament."

By Mike McAllister, PGATOUR.COM

IRVING, Texas – Jordan Spieth may have shown his age in the last four holes, but overall, the 17-year-old amateur still had an impressive week in his second start at the HP Byron Nelson Championship.

Spieth went bogey-double bogey-bogey-double bogey in the final four holes in Sunday’s final round. He wasn’t alone in his struggles at TPC Four Season Resort’s closing stretch, but it was a tough day for the high school graduate.

“I was humbled by the this back nine.” said Spieth, who will be a University of Texas freshman this fall. “ … It’s hard. It stings right now, it really does.”

Spieth shot a 7-over 77 in the final round to leave him at 6 over for the tournament. He was still 1 over through 14 holes, which still gave him hope to make a move. Instead, he just moved backwards.

“I’m proud of the way I hung in there until the last four holes,” Spieth said.

Spieth started the final round just four shots off the lead. But a bogey at the opening hole was a foreshadow of struggles to come. Spieth eventually posted three double bogeys on the day, along with five bogeys.

But he also had four birdies, and 20 overall for the week. Defending champion Jason Day led the field this week in birdies with 22.

Another big crowd followed Spieth, who had big troubles off the tee Sunday. He hit just four of 14 fairways.

“I was everywhere today,” Spieth said. “I probably played a shot left-handed. I hit probably 30 trees. … It just wasn’t there with the driver today. Had I hit some fairways today, I think I could’ve shot a couple under and had a good shot.”

Last year in this event as a 16-year-old, Spieth became the sixth-youngest player to make a cut at a PGA TOUR event and eventually finished tied for 16th.

IRVING, Texas – With just five holes left in his round, Jordan Spieth has posted 20 birdies this week. That’s the second-highest total among all players in the field this week (Jason Day has 22 birdies as he plays his final hole).

Unfortunately, the 17-year-old amateur has negated all those red numbers with four double bogeys and 12 bogeys. That’s why he’s even par for the tournament, which leaves him four shots off the lead.

Still, it’s an impressive total for Spieth, who missed his high school graduation ceremony. Birdies have been in short supply this weekend, but Spieth has nine birdies thus far in the final two rounds.

Click here to follow the rest of Spieth’s round on ShotTracker

IRVING, Texas – Jordan Spieth, the 17-year-old amateur from Dallas, has suffered a big blow as he seeks to make history on Sunday.

Spieth just double bogeyed the par-4 eighth when he found the greenside bunker with his approach shot, then three-putted from inside five feet. That drops Spieth to 1 over for the tournament.

It’s the fourth double that Spieth has posted this week, and his third in the last 23 holes this weekend.

Until the double, Spieth had been even par on his round, and was 1 under for the tournament, just three strokes off the lead. But with only a few scoreable holes left before he reaches the tough final five holes, Spieth is running out of time.

If Spieth were to win, he would be the youngest winner in at least 111 years.

The top of the leaderboard has changed. Ryan Palmer has suffered another bogey and is now at 3 under. That leaves Joe Ogilvie and Ryuji Imada as the tournament leaders at 4 under as the final groups approach the turn.

Sergio Garcia, who is playing with Palmer in the final group, is 5 over on his round and is 1 over for the week.

By Mike McAllister, PGATOUR.COM

IRVING, Texas -- He birdied the first hole. Then the second hole. Then Jordan Spieth started thinking.

As he stood on the tee box at the third hole Saturday, having climbed to third place on the leaderboard, he turned to his caddie and asked: "Why can't we just birdie every single hole today?"

Reality soon kicked in for the 17-year-old amateur from Dallas. He gave away those two strokes with a double bogey at the par-4 fourth when he got a bad break off the tee, then made a poor decision out of the fairway bunker. A bogey at the ninth dropped him under par for his round.

But give the kid credit. He battled his way to a 2-over 72 in tough third-round conditions of the HP Byron Nelson Championship and will go into Sunday's final round at 1 under for the tournament, which at least gives him a long-shot chance to make a run at the leaders. He’s tied for eighth, four shots off the lead held by Ryan Palmer.

Spieth experienced a little bit of everything Saturday. Five birdies. Three bogeys. Two double bogeys. A 25-foot putt for birdie. Several "amateur decisions" (in his words). A great start. And a nice finish that included a birdie at the par-3 17th to keep him under par.

"I'm happy with the way it started and the way it finished," Spieth said.

About the only thing he failed to do was attend his high school graduation ceremony at Jesuit College Preparatory School, which started right about the time he finished his round.

He seemed OK with that.

"I'm happy to be officially graduated," said Spieth, who will be a freshman at the University of Texas this fall. "It's time to move on to college."

He still has work to do Sunday, though. Last year in this event, when he was 16 and became the sixth-youngest player to make a PGA TOUR cut, he finished tied for 16th. He's looking for a better result this year, although he knows he'll be several shots off the lead.

"We'll see what happens if I can get out there and post a few under," he said. "I just want to post a solid number."

There were several times on Saturday that Spieth's round could have really gone south. But he kept fighting back.

After the double bogey at the fourth hole, he produced four straight pars. After the bogey at 9, he bounced back with a birdie at the 10th. After his double bogey at 11 when he found the water with his tee shot, he came back with two pars, then a birdie at the 15th.

After a bogey at the par-5 16th left him steaming as he walked off the green -- "I'm sititng OK in the fairway and somehow turned it into a 6," he said -- Spieth had a chance to cool down as he waited to hit his tee shot at the 17th.

He put the ball inside 10 feet. And as he stood over the birdie putt, a huge gallery staring at him, he wondered one thing.

How long is it going to be if this goes in?

"I really wanted to make it just to hear the roar," he said.

He did. Another impressive day for the 17-year-old.

“I only really had 4 or 5 bad swings,” he said. “That resulted in playing five holes in 7 over par. … But my putter’s keeping me in it.”

IRVING, Texas -- Texas native Ryan Palmer is hanging tough in windy conditions while local favorite, teenage amateur Jordan Spieth, is dropping back.

Although Palmer is having trouble finding fairways -- he hit just two of his first 10 on Saturday -- he's even par on his round and 8 under for the tournament. That gives him a two-shot lead over playing partner Sergio Garcia, who suffered two bogeys on his front nine and has yet to post a birdie today.

Nick Watney, Ryuji Imada and Joe Ogilvie are tied for third at 4 under.

Spieth, the 17-year-old from Dallas, has had a rollercoaster round that includes two double bogeys and three bogeys. He's been able to minimize some of the damage with four brides, but he's still 3 over on his round.

Spieth's high school graduation starts at 5 p.m. ET. He's on the 17th hole now, so he likely will not miss much of the ceremony.

Just eight sub-par rounds have been posted thus far, with Arjun Atwal's 67 the low round in the clubhouse.

Take away the second round and Jeff Overton would be 9 under. Of course you can’t do that, but Overton has nonetheless found a way to recover from his 74.

Through his first nine holes on Saturday, Overton is 3 under and as a result has moved back into contention just two shots back.

The two players Overton is chasing? Ryan Palmer and Sergio Garcia, both of whom are 1 over through six holes.

As for Jordan Spieth, the 17-year-old high school senior who began the day five shots back? He raced out of the tee box with birdies on each of his first two holes, but he gave those back on the fourth hole with a double bogey. Spieth then made another bogey on the par-4 ninth to make the turn in 1 over on the day.

The good news for Spieth, of course, is that the leaders have gone backwards as well and he’s still just five shots back.