Brooks Koepka had stem cell treatment on knee during offseason

Behind the scenes of Brooks Koepka's Body Issue shoot (3:53)

Take a look behind the scenes of Brooks Koepka's shoot for the Body Issue, and listen to him discuss his thoughts on a stereotypical golfer's physique. (3:53)

LAS VEGAS -- Brooks Koepka spent the majority of his short offseason recovering from stem cell treatment on his left knee, he said Wednesday.

Koepka, the No. 1 player in the world golf ranking, returns to competition this week in the Shriners Hospitals for Children Open in Las Vegas.

After his pro-am round Wednesday, Koepka said he had treatment on his patella on Aug. 25, the day after the PGA Tour season ended at the Tour Championship. He said he was limping for a few days because the treatment was painful, but he was excited about finally feeling whole.

"My knee was bugging me from about March on," Koepka said, adding that the final four months were a "struggle."

Koepka won three titles last season, including the PGA Championship -- his fourth major.

He is the third player from the top 10 in the world golf ranking to have work done on his knee during the offseason, joining Dustin Johnson and Tiger Woods. None was too serious, as Woods plans to return in three weeks at the new tournament in Japan. Johnson is likely to return at the Hero World Challenge in the Bahamas the first week of December, followed by the Presidents Cup in Australia.

Koepka never talked about injury during the season. He said his knee made it difficult to walk down hills and that it kept him from practicing. He returned to practice a little over a week ago and feels this is the most prepared he has felt going into a tournament in some time.

With all that, he still managed to have three wins, lead the PGA Tour money list and join Jack Nicklaus, Woods and Jordan Spieth as the only players to finish among the top four in every major. Koepka was runner-up at the Masters and U.S. Open.

It just wasn't good enough to be voted PGA Tour player of the year. That award, voted on by players, went to Rory McIlroy, whose three victories included The Players Championship and the Tour Championship, which gave him the FedEx Cup for the second time.

"I don't play for awards," Koepka said Wednesday. "I play to win tournaments."

He also used an NBA reference, suggesting everyone knows that LeBron James has been the best in basketball for the last decade or more.

"LeBron has won only four MVPs," Koepka said. "I'm pretty sure he's been the best player."