Gary Sheffield sprained his left ankle and took a 96 mph fastball off his left arm in the same inning yesterday, yet he wouldn’t acknowledge it was a tough day for him.

After all, victories are the best painkiller on the market.

“It don’t feel that bad after a win,” Sheffield said of his ankle following the Yankees’ 6-0 victory over Oakland.

The Yankee right fielder suffered a high left ankle sprain in the fifth inning while chasing an Eric Chavez liner. While running into the gap, he slipped on the wet grass and fell backwards.

However, a 26 mph wind that was blowing left to right carried Chavez’s ball back toward him. He had the presence of mind to catch the ball and hold Mark Kotsay on first base while falling onto the ground.

“Yeah, that’s the most important thing,” he said. “You’ve gotta catch the ball and try to get it back in. Luckily, everything came out OK.”

Sheffield said he had never before made a catch sitting down. After the play, he walked around the outfield for a few moments until assistant trainer Steve Donohue and Joe Torre jogged out to check on him.

He untied his shoe and laid back down on the grass until Donohue checked out the injury.

“It’s fine,” he said. “I’ll be in there (tonight).”

Sheffield remained in the game and took a heater from Oakland righty Rich Harden high off his arm in the bottom of the fifth. He received ice on the ankle after the game but walked out without crutches.

He’s obviously one of the toughest players around, having survived a bullet wound from years ago. Last season, he played through an excruciating shoulder injury to manage 154 games.

Coincidentally, he said Saturday he’s determined to stay in the lineup.

“I just try to look at myself as I’m accountable every day,” he said that day. “I’m gonna get out there every day whether I feel good or not.

“I feel like I can do something to help win a ballgame, and that’s what I try to do every day.”