The two-time NL Cy Young Award winner walked through the clubhouse without a noticeable limp and rode a stationary bike before Saturday's exhibition game against Oakland was rained out.
"Just a little sore, a bruise," Lincecum said. "I'm able to walk on it and I'm moving around fine. I think the trainers are going to want me to take it slow and probably take it day by day to see how it progresses."
A night earlier, Lincecum was on the ground near the pitcher's mound writhing in pain after getting struck by a hard-hit grounder from Daric Barton in the fourth inning. Lincecum tried to run toward first but immediately fell, unable to put any pressure on his leg. He limped off the field with the assistance of two trainers and underwent X-rays, which were negative.
Giants manager Bruce Bochy said Lincecum appears fine and is hopeful the right-hander will start Thursday in Arizona.
"Right now I think we're pretty comfortable that he'll be OK to go," Bochy said. "We'll keep an eye on him, but he's walking around pretty good. That's good news.
"I think where it hit that part of the knee -- not that he's not really sore -- but after an hour or so it seems it calmed down quite a bit."
Lincecum signed a $35 million, two-year contract in late October to stay with San Francisco and is trying to rediscover his Cy Young form after helping the Giants win the World Series in 2010 and 2012. He went 10-14 with a 4.37 ERA and 193 strikeouts over 32 starts last season, his third straight with a losing record.
The former San Francisco ace pitched four innings and allowed one run on three hits against the A's on Friday before getting hit in the knee. The ball ricocheted off Lincecum and rolled back near catcher Buster Posey, who threw to first for the out as Lincecum fell to the turf.
"I've had plenty of balls hit me before off the mound," Lincecum said. "Afterward the feeling came back and you realize it's not as bad as it feels."
Because there was only minor swelling and lingering soreness, Lincecum didn't see any reason he would miss his start against the Diamondbacks. But he said he was leaving the decision up to the Giants' trainers.
"I don't want to miss it and right now I feel like I should be fine by the time that comes around," he said. "I've iced probably four times already just to keep the swelling down. I'll see how it progresses."