A two-inning simulated game was followed by base running drills, which was followed by an hour of sitting around, which was followed by regular batting practice -- all of it taking place amid the cool air off San Francisco Bay. By the end of Thursday's activity, Barry Bonds was pleased with how his knee responded, but not pleased enough to be able to pinpoint his return to the San Francisco Giants' lineup.

Asked early Thursday evening if it was realistic to expect his return to occur this weekend, Bonds said, "It's not unrealistic, but right now it's just [a matter of] how I recover after today and possibly tomorrow."

Bonds is in the final stages of a lengthy, difficult rehabilitation from three surgeries on his knee. He last played for the Giants in October 2004, finishing the season with 703 career home runs, which ranks third on the all-time list.

Shortly after 2:30 p.m. Thursday, with team executives and Manager Felipe Alou looking on, Bonds stepped into the batter's box at SBC Park to face a live major league pitcher -- teammate Kevin Correia -- for the first time in his rehabilitation. The exercise seemed perfectly real -- right down to the lack of hittable pitches.

Over two simulated innings, Correia threw 21 pitches, only seven of which were offered at by Bonds. Of Bonds's seven swings, he put three balls in play, one of which cleared the wall in right field -- a simulated home run. In between "innings," Bonds took additional batting practice against a coach.

"The swing is okay," Alou said afterward. "I didn't even pay attention to that."

The issue is not Bonds's swing, but the health of his knee. Both the Giants and Bonds have much at stake as they look ahead to the 2006 season: the team has $18 million invested in him next season, while Bonds remains within striking distance of the home run records of Babe Ruth (714) and Hank Aaron (755).

For the sake of both, Bonds's doctors are urging caution. He spoke with one of them following Thursday's workout, but before he addressed the media.

Bonds acknowledged his knee his felt "a little stiff" at times over the last few days, mostly during the periods of inactivity that have followed his intense on-field workouts. He plans to work out again Friday afternoon, with more emphasis on base running and defense "He's going to have to feel like he's ready," said Giants General Manager Brian Sabean.