Has Barry Bonds waved goodbye to his chance at catching Hank Aaron? Stephen Dunn/Getty Images
	Heirs to the Throne? Top 11 Active HR Leaders Player Age HR 1. Barry Bonds 40 703 More operations lately than Joan Rivers. 2. Sammy Sosa 36 578 He's gone downhill since hitting 64 in 2001. 3. Rafael Palmeiro 40 552 He's just hanging on for 3,000th hit. 4. Ken Griffey Jr. 35 503 Not gonna happen. 5. Jeff Bagwell 37 449 He'll have to do it with one arm. 6. Frank Thomas 37 436 The Big Hurtin' will be lucky to get to 500. 7. Juan Gonzalez 35 434 Yes, he is still an active player. 8. Jim Thome 34 424 Just went on DL with ominous back problems. 9. Gary Sheffield 36 418 Still fearsome, but for how much longer? 10. Manny Ramirez 33 397 Fenway slugger has an outside shot. 11. Alex Rodriguez 29 391 Pitcher-friendly Yankee Stadium won't help.

We know nothing, really, about Barry Bonds' future. Except that, right now, it's a heck of a lot harder to see than it was four months ago.

The man who would pass Henry Aaron on baseball's all-time home run list has had a difficult start to 2005: surgeries, steroids rumors and a never-ending rehabilitation. For Bonds, the new year has been a novelistic series of unfortunate events that has thrown what once was nearly a given into some serious, history-altering doubt.

Last year, after Bonds hit 10 homers in the month of April, the question around baseball was "when" would Bonds pass Aaron to become the sport's home run king, not "if?" When he ended the season at 703 career homers, just 52 short of Aaron, everyone started to project when the historic event would happen.

Now, after Bonds' third knee operation since the beginning of the year, "if" has taken the lead once again. A big lead.

Age and injury are Bonds' biggest enemies at this point, and they seem to be working together. Like so many athletes of his age, Bonds is beginning to break down. Blame it on the fact that he'll be 41 in July. Blame it, if you believe so, on the use of performance-enhancing drugs.

Whatever the case may be, that third operation he had on his ailing knee Monday morning was the latest indication that Bonds has a long way to go before he hits No. 756. His Web site showed a picture of him earlier this week resting in a chair at home, his right leg propped up on a pillow. He looked far from ready to play.

But even when he's fit again -- nobody knows when that will be, but at this point, July looks optimistic -- how can he be the same player?

For the past five years, Bonds has averaged nearly 52 home runs a season. He hasn't had fewer than 45 homers in any of those seasons. Except for the occasional problem his balky knees gave him, he's been relatively healthy during that stretch. He hasn't played fewer than 130 games in any of those years.

Still, history shows us that age alone is a huge obstacle. Ted Williams hit 29 home runs in 1960, most of them after he turned 41. It was the most prolific home run season ever for a player 41 or over. Reggie Jackson hit only 15 homers the year he turned 41, which seems like a pretty high goal for Bonds this year, especially if he doesn't come back until July.

And, when Bonds turns 42 next year? Carlton Fisk smacked the most homers for a 42-year-old, in 1990. He had 18.

If his age and his health and the inactivity of being on the disabled list were all Bonds had to deal with, Aaron's mark wouldn't suddenly seem so far away. But being Barry Bonds is a lot more taxing than that.

The BALCO steroids-distribution case is still in the headlines. Bonds has been a central figure in that almost from its beginnings. All the steroids rumors apart from BALCO that have dogged him over the years have taken their toll. Bonds looked beat up and defeated in that infamous Spring Training session with reporters when he declared, "I'm tired. Just tired. My family's tired."