Torres was hit by a ball during Friday night's loss at Florida, resulting in a bruised right leg. The switch hitter is batting .228 with three homers in 85 games.
San Francisco also was missing outfielder Carlos Beltran for Saturday night's game against the Marlins. Beltran hasn't played since he left last Sunday's 3-1 win over the Phillies with a strained right hand.
Manager Bruce Bochy said he was waiting to hear from Beltran and team trainer Dave Groeschner after the slugger took swings in the indoor batting cage Saturday.
"He feels better, but that's all I have for you now," Bochy said.
Belt joins the Giants for the fourth time this year. He was expected to arrive before the matchup with the Marlins.
Belt was San Francisco's opening-day first baseman this season. He has a .218 batting average, two homers and seven RBI in 31 games.