 Five days after getting released by the Twins, the San Francisco Giants signed Whiteside. He spent the rest of the year with the Triple-A Fresno Grizzlies of the Pacific Coast League. In 49 games, the most by any catcher with Fresno in 2008, Whiteside batted .238 with 36 hits, two home runs, and 22 RBI. He had a .986 fielding percentage but only threw out seven percent of attempted base-stealers. In 57 games (175 at bats) between Rochester and Fresno, he hit .229 with 40 hits, three home runs, and 23 RBI.
