Barry Bonds' knee is hurting again. The picture does a good job of showing his discomfort:

Bonds is day to day. The seven-time NL MVP had surgery on his left knee after the 2004 season ended, then underwent three operations on his right knee last year.

Fans booed when A's starter Esteban Loaiza walked Bonds on four pitches leading off the second. He scored on Steve Finley's double to left-center two batters later, but was clearly uncomfortable running the bases and hobbled home with a grimace on his face.

He's been hitting and running somewhat better lately, even stealing a base the other day. The problem, of course, is that he might start pushing himself too much, and something like this happens. The Giants get Monday off, so he'll have a day to recover if it's minor. At this point, however, you just don't know if the knee is going to go for good.