(AP Photo/Matt Slocum)

SONOMA, Calif. (AP) -- Will Power used the time before the IndyCar season finale for a little rest and relaxation. That backfired when a strong wave took him by surprise while swimming at Half Moon Bay in Northern California. 

Power had a limp from a hyperextended left knee when he arrived at Sonoma Raceway for Sunday's championship-deciding finale. He's fifth in the standings, 68 points behind Team Penske teammate Josef Newgarden, but the race is worth double points and Power is mathematically eligible to win the title. 
But will that knee injury pose a problem? 
"No problem," the Australian said. "As long as (the knee) is bent, it's no problem. It's just straightening it is the issue. Good news in the car is you're always bent knee. It's a bruised bone so you can't really do any more damage, so you've just got to fight through the pain if there is any."
Power has a tough assignment Sunday if he's going to claim his second IndyCar title. He's got teammates Newgarden, Helio Castroneves and Simon Pagenaud ahead of him in the standings, as well as four-time champion Scott Dixon. 
Even though the race is double points, he needs the others to falter while Power must score maximum points by winning the pole, leading the most laps and winning the race. Even if he does all that, Newgarden must finish 13th or worse. 
Power has won five poles at Sonoma, and three races on the 2.385-mile, 12-turn track. 
"My aim is to qualify on pole and win the race," he said. "That's the aim. That gives me a shot at winning this championship if circumstances play out."