Details on Rory McIlroy’s new, never-before-seen TaylorMade ‘Proto’ 4-iron

Rory McIlroy is switching to a mysterious new 4-iron that he says provides the same speed as his old 4-iron but produces a higher ball flight. He was expected to have the club in the bag starting with Round 1 at this week’s Valero Texas Open.

After working with legendary swing coach Butch Harmon in Las Vegas recently, McIlroy also stopped by TaylorMade’s “The Kingdom” fitting facility in Southern California, where he tested out some new prototype irons.

Apparently, McIlroy, who currently is ranked 29th on the PGA TOUR in approach shots over 200 yards, liked what he saw, because he’s set to start using a new “Proto” 4-iron as he tees it up at the Valero with one eye on next week’s Masters.

GolfWRX.com first spotted McIlroy using the club at TPC San Antonio on Wednesday, when he arrived on-site after a scouting trip to Augusta National the day prior.

TaylorMade has yet to comment on the new “Proto” club, but for McIlroy, it will replace his longtime P-760 4-iron, which was originally released to the public in 2017. McIlroy has been using a P-760 4-iron at the top-end of his iron set, to go along with a set of TaylorMade “Rors Proto” blade irons in his 5-PW.

To McIlroy, the new 4-iron feels more like his set of “Rors Proto” blades than his previous P-760 design does.

"They performed really well," McIlroy said Wednesday at the Valero. "It’s just as fast as the 760 that I was using. Launch is a little higher actually, which was surprising, and it’s just sometimes I felt like when I hit my 5-iron in the blade and then the 4-iron in the 760 it was such a different feel. To go from a 5-iron now to that (new) 4-iron, it feels a little closer to what I feel in the 5-iron.

“So just a little bit more responsive,” he continued, “but didn’t lose any performance from it, which is great. Yeah, it will be in the bag this week.”

It remains unknown whether the "Proto" club will be released to the public, and if so what it would be called. Either way, McIlroy will give it a go at TPC San Antonio.

According to Trackman data on the driving range Wednesday, McIlroy hits the new 4-iron over 250 yards, with ball speeds around 155 mph. Plus, with the new 4-iron launching even higher than before it could prove useful at Augusta National, where stopping power is critical for holding the firm and fast greens.