Colin Montgomerie ... Making his first start in a PGA TOUR event since the 2010 PGA Championship at Whistling Straits, which means that it's his first start on the circuit since his induction into the World Golf Hall of Fame last year. After going winless in 71 starts in majors, the Scotsman picked up his first title in a major at the Senior PGA Championship in May, which exempt him into the field at Valhalla. He's thrived on the Champions Tour since turning 50 years of age on June 23, 2013. Currently second in the chase to the Charles Schwab Cup thanks to two wins (both majors), two seconds and another six top 10s.
Koumei Oda ... With fellow Japanese native Hideki Matsuyama focusing on competing on the PGA TOUR this season, that's opened the door for the 36-year-old Oda. He leads the Japan Golf Tour's Order of Merit and sits second among the Japanese behind Matsuyama in the Official World Golf Ranking (at 62nd overall). All of Oda's seven cuts made in nine starts on the JGTO this year are top 15s, including one win and two seconds. In addition to earnings, he leads his circuit in scoring average and putting.
Alexander Levy ... With a win at the Volvo China Open in April, he seemed to have embarked on a similar arc as fellow 24-year-old Frenchman Victor Dubuisson, whose rocket took flight last fall in Turkey. Levy, who was born in California, has played steady, unspectacular golf since, but that breakthrough victory remains his only top 10 of the year. Currently 25th in the Race to Dubai, he's also 15th on the European Tour in distance off the tee, 41st in greens hit and 40th in scoring average.
Edoardo Molinari ... Suffice it to say that he's back. He polished off a career year in 2010 (when he won twice) with a spot on the victorious European Ryder Cup team. In 2012, he suffered a wrist injury for which he'd finally have surgery right around this time last year. The 33-year-old sits 28th in the Race to Dubai this season on the shoulders of four top 10s, including a T7 at The Open Championship. Ranks 50th on the European Tour in greens in regulation and 37th in scoring.
Shane Lowry ... The 27-year-old from Ireland hasn't won since the 2012 Portugal Masters, which validated his breakthrough win as an amateur at the 2009 Irish Open, but he's been a factor of late when surviving the cut. All of his six cuts made in his last eight starts have gone for a top 25. The last two were top 10s, including a T9 at The Open Championship. Solid throughout his bag.
Ross Fisher ... First appearance in the PGA Championship since 2011. The Englishman is a five-time winner on the European Tour. He went winless for three seasons until taking the Tshwane Open in South Africa in early March. As a survivor of PGA TOUR qualifying school in 2012, he's in the annals as a member of the last class before the current qualifying process was adopted. However, in only 15 starts while juggling status aboard, he finished 161st in the FedExCup standings. Now 33 years of age and a non-member again.