Wolverines head coach Brady Hoke says it was important for Isaac to move back to the Midwest to be closer to his mother and his family. Isaac is from Shorewood, Illinois. It is unclear if he will sit out this season to comply with NCAA transfer rules or seek a hardship waiver to be eligible immediately.
Isaac appeared in all 14 games for the Trojans in the 2013 season, rushing for 236 yards on 40 carries with two touchdowns. He finished his high school career at Joliet Catholic Academy in Illinois with a school-record 5,305 yards rushing.
Michigan's running game has been spotty the past two seasons. This season's returning rushing leader is quarterback Devin Gardner (483 yards). Among tailbacks, highly touted freshman Derrek Green had 270 yards and averaged 3.3 per carry in a disappointing season.
Isaac was a steady contributor in USC's backfield as a freshman, but emerged from spring football behind Javorius Allen and Tre Madden on new head coach Steve Sarkisian's depth chart. Allen and Madden both have two years of eligibility remaining with the Trojans, and Isaac's hard-nosed running style might be better suited to Big Ten football than Sarkisian's up-tempo scheme.
Allen seized the starting job at Tailback U. in the second half of last season, rushing for 13 touchdowns and compiling four 100-yard performances in USC's final six games. Madden, a converted linebacker, got off to an outstanding start last season before hamstring injuries slowed him.
USC also has promising sophomore Justin Davis, who missed the second half of last season and spring ball while recovering from an ankle injury.