SAN FRANCISCO — Barry Bonds once seemed on an inevitable march toward becoming baseball's home run king.

The San Francisco slugger homered at a dizzying rate, sending pitches both good and bad over outfield fences. Now he's lucky to hit one out once a week.

What only a few years ago appeared a relatively simple task has become daunting: 40 home runs to tie Hank Aaron's record of 755.

"If my health feels good and I feel like I can play, then I'm going to play," Bonds said Monday before the Giants played at Florida, then minutes later became a little less definitive. "If I'm healthy enough, it's a good shot. It's still a long way away. We're still in May. Anything can happen between now and then."

He's playing on a surgically repaired right knee and has bone chips floating in his left elbow. Then there are the two investigations into his alleged steroid use.

"I don't know why people think he's not going to get Aaron," Hall of Famer Reggie Jackson said. "He needs 40 home runs, so sometime in 2007, he's going to go by Henry.

"I don't know if George Mitchell will chop him with the investigation, but if he doesn't test positive, or they don't get something on him, it's just a matter of time."

Bonds took the first step in that direction Sunday, when he hit his 715th homer to move past Babe Ruth and into second place on the career chart. He did it with a 445-foot, two-run shot to center off Byung-Hyun Kim in the fourth inning of a 6-3 loss to Colorado.