US PGA Tour commissioner Tim Finchem denied there was pressure from the tour pushing Tiger Woods into competing at the Players Championship, an event he withdrew from due to injury.

Former World No 1 Woods, who has not won a title in 18 months since his infamous sex scandal erupted, pulled out of the $9.5 million event after nine holes in Thursday's first round due to a sore left knee and Achilles tendon.

"It's always important for Tiger to be a part of the tour because he's Tiger Woods, but the idea that we would pressure him to play is ludicrous," Finchem told CNBC late on Friday. "We don't pressure any player to play the tournament.

"In this case, the suggestion is somehow he was hurt and we got him to play anyway. Tiger doesn't enter a tournament unless he thinks he can win."

Woods had barely played golf since last month's Masters, where he shared fourth for the second year in a row in the first major event of every season.

Finchem said the tour benefits from Woods being healthy and not trying to return too soon from an injury.

"I hope he's healthy enough to play," Finchem said. "Just look at it from the health of the tour standpoint. If he's an active player it helps us out a lot. He doesn't have to come back and dominate like he did. He needs to play.

"My concern is, where are his injuries going to go? And he doesn't know what the answer will be and we won't know for a while."

Woods limped off on Thursday saying he needed medical advice before having an idea when he might play again.

"Give me a few days to see what the docs say, and we'll take a look at it," he said.

The withdrawal, Woods' second in a row at the Players after a 2010 pullout due to a neck injury, renewed concerns that the 14-time major champion might never again produce the form that made him a challenger to the all-time record of 18 majors won by Jack Nicklaus.

"Tiger looked like he was in pain," said Thursday playing partner Matt Kuchar. "Looked like you could tell he was walking quite slowly. He was just last to get to his ball every time as he was just walking so gingerly."

"Nobody really knows in how much pain he was," said former World No 1 Martin Kaymer, who also walked with Woods.