Tiger Woods has made such a great recovery from last April's spinal fusion surgery that many might wonder why he did not have the procedure sooner.

But Woods said on Saturday he was not prepared to risk the operation until he basically had no other choice if he wanted to have a chance of living pain-free and playing competitive golf again.

"This is uncharted territory," Woods said after moving within one stroke of the third-round lead at the Valspar Championship in Palm Harbor, Florida.

"No one has ever had a lower lumbar fusion where I had it and then come out here and played.

"I didn't want to go there. That was a last case resort and ended up being the only option I had left.

"We exhausted all the non-surgical options. My disc was still intact, so we're trying to save the disc and I just never know about the future."

Swinging fluidly, Woods on Saturday generated more club speed than any other measured swing on the PGA Tour this year - 129 miles per hour - with his drive on the 14th hole at Innisbrook Resort.

He carded 67 for an 8-under 205, trailing only leader Corey Conners of Canada.

Whether or not he wins on Sunday for what would be his 80th career victory on the PGA Tour, the 42-year-old has already showed in his fourth official tournament since the fusion that he is not a spent force.

Woods' health is a far cry from this time last year, when he said he could barely climb out of bed.

He said that during his worst times he often thought about life before his back injury.

"A lot of times I did think about it. I was hoping something would take the pain away, so I could get up out of bed and walk again. I was living from minute to minute. You have no idea how hard it was."

Reuters