THOUSAND OAKS, Ca. — Bernhard Langer has a left knee injury that could force him to withdraw from the PowerShares QQQ Championship, the inaugural Charles Schwab Cup Playoffs event.

“I’m not sure I’ll be able to play tomorrow, but I’ll make that call at noon when my tee time is,” Langer said Thursday. “For right now, I’ve been getting treatment and trying to stay off my knee.”

Simply, the decision will come down to whether the he can hit the ball.

“I tried yesterday and it didn’t work,” Langer said. “I can’t transfer my weight. I can’t put any pressure on my left knee.”

The 59-year-old German star leads the 50-and-over tour with tour four victories and has wrapped up the season money title with $2,697,459.

“I had an MRI on Monday because I couldn’t walk properly and just had problems,” Langer said. “Obviously, haven’t hit a shot yet, haven’t been out on the course. I walked it, but I haven’t hit a shot yet because I can’t, I can’t put much pressure on my knee. Walking these hills is very difficult, especially downhill.

The top 72 players on the money list earned a spot at Sherwood Country Club, the former site of Greg Norman‘s Shark Shootout and Tiger Woods’ event that is now called the Hero World Challenge. The playoff field will be cut to 54 for the Dominion Charity Classic next week in Richmond, Virginia, and to 36 for the Charles Schwab Cup Championship the following week in Scottsdale, Arizona.

Each dollar earned in the first two events is worth two points and will be added to the regular season total. At the Charles Schwab Championship, points will be reset so that the top five only have to win to capture the Charles Schwab Cup. Langer has a big enough advantage over second-place Miguel Jose Jimenez that he would keep the lead event even if he doesn’t play this week.

“I came all the way here from south Florida and committed to play,” said Langer, a three-time Cup champion. “But if I’m going to do long term damage, the last thing I want to do is try and play and do further damage and then I can’t play next week or the following week, which that would really be bad if I can’t play the Schwab Cup. You know, the priority is to get my health. You can’t play golf if you’re not healthy. The game is hard enough when you’re healthy, you don’t need to be injured.”

Fred Couples is attempting to play after sitting out eight months with a back injury.

“I’m honestly hoping to get through this,” the 57-year-old Couples said. “It’s one of my favorite golf courses, so I found out last week that I was in the playoff. I haven’t played since February, so I thought, `You know, I’ll commit.’ I hit balls on Friday before I committed and actually felt OK.”

John Daly qualified 70th. He has five top-25 finishes in 14 starts since turning 50.

“All of us old guys have seen this course a few times, so there’s no home-field advantage,” Daly said. “I’ve heard nothing but great things about the changes and everything.”