You'd never know Barry Bonds was lost, and that's the fascinating thing. Bonds over the years has played at such elite levels with such a consistent absence of expression, such a crafted stoicism, that there's just nothing about his body language that would now signal a problem, mechanical, emotional or otherwise.

	Bobby Bonds possessed a rare blend of speed and power.

But Bonds is lost, as sure as he sits in a San Francisco Giants uniform. He plays baseball now in the absence of a mentor so completely locked into his game that, until this year, Bonds could expect a phone call to the dugout immediately after a lousy at-bat, telling him what he did wrong.

"I've never played baseball without my dad," Bonds told reporters in Chicago the other day. "My dad's always been there. Now I play alone."

Father's Day, and the news is not forgiving.

Bobby Bonds' battle against lung cancer is not going well. The cancer has spread, and Bobby, stationed mostly in a hospital in the San Francisco area, has had trouble breathing. Last year, the 56-year-old former All-Star outfielder also underwent surgery to remove a cancerous tumor from his kidney.

For the father, it is the ravage of the disease. For the son, it is the pain of separation.

To the sport, it's a loss of another kind. For years, Barry Bonds has been a constant in the game, a player almost preternaturally focused on the business at hand. Just now, he's a guy whose heart and head are trying to be two places at once almost all the time. And whether or not the public would ever notice, those close to Bonds certainly do.

Teammates and peers speak of Bonds essentially going from the playing field to the hospital to be with his dad, then turning around and doing it again the next day. Though Bonds always has been given a wide berth in the Giants' locker room, the feeling these days is that it is the respectful thing to do, rather than the product of Bonds' aloof personality among his colleagues.

But the bottom line is that Barry doesn't have Bobby, not in the way the younger Bonds is accustomed to having his father in his life. Through Barry's professional career, Bobby has essentially been his unpaid hitting coach (though he was paid in that capacity for a few years with the Giants). The two men's relationship was forged in the game itself.

Barry Bonds has said in the past that he resented his father's absence in his younger life, that the Bondses began growing closer only when Barry went to Arizona State to play college baseball. From that point on, of course, baseball has been the thing. It has brought Barry glory and money beyond anything he ever imagined. But it also brought a father closer to a son.

As recently as last fall, Bobby Bonds was on hand to watch Barry play in the World Series. This year was different from the start. Not only has Bobby not been seen around Pac Bell Park, but Barry says his father generally is too weak to follow the games much at all. The two speak every day, but those dugout phone calls and late-night conversations to fine-tune Bonds' swing are gone.

To the casual eye, none of this has made the slightest bit difference in Bonds' game. He has raised his batting average to .313, continued to belt home runs when he gets pitches and to emotionlessly take his walks when he doesn't get them. On the surface of things, it's the same Bonds all over.

But Barry has begun to acknowledge the toll, even as he steadfastly refuses to ask special dispensation for it. The Bonds who spoke in Chicago this week was a man edging closer to the end of his emotional rope; speaking of his amazing athletic consistency, given the circumstances, he said, "I've been able to hold it, but I don't know for how much longer I'll be able to hold it back."

Bonds is worried that he'll snap, that he'll "flip out or go crazy or pick a fight because of all the frustration and anger I have in me." More likely is that Bonds simply won't be able to summon the focus at some point, and that's natural. His own teammate, pitcher Jason Schmidt, endured a similar ordeal as his mother battled cancer for a year before dying in April, and Schmidt says the focus can be the most difficult thing to obtain.

Barry Bonds is dealing with the threat of loss on a different level; for months now, he has been slowly losing his baseball touchstone. It may be the most profoundly affecting experience of his professional life, and that could prove true whether or not anyone is ever able to tell it from the outside looking in.

The phone in the dugout doesn't ring anymore. It's the absence of that ring that Bonds hears lately.

Mark Kreidler is a columnist with the Sacramento Bee and a regular contributor to ESPN.com