SAN FRANCISCO -- Jeremy Affeldt threw a light bullpen session Friday afternoon and Giants manager Bruce Bochy said the left-handed reliever's sprained left hamstring is improving.
"Jeremy's coming around," Bochy said. "He feels much better. Hard to say what day [he'll return]. It could be [Saturday] -- that's how much he's improved -- or it could be a couple more days."
Bochy said Affeldt would not be used in Friday's series opener against Arizona, but depending on how Affeldt feels Saturday, he could be available for Saturday's game.
Affeldt (2-3, 3.12 ERA in 17 appearances) sprained his hamstring Sunday against the A's in the eighth inning while trying to field a sacrifice bunt by Daric Barton, who led off the inning. Affeldt faced two more batters before leaving the game.