Michigan football target Ty Isaac, a five-star running back, chooses USC over the Wolverines

Isaac reportedly had USC, Notre Dame and Michigan in his final three.

The 6-foot-2, 220-pound Isaac is rated the top running back in the 2013 class by Scout.com, and is the No. 2 running back according to Rivals.com.

In an interview with Scout.com's Allen Trieu, Isaac explained his decision.

"Honestly, Saturday or Sunday, I kind of woke up and knew," Isaac told Scout. "I ran through every scenario in my head and thought about it all and I was just like, football is supposed to be what it's going to be.

"As long as I do what I know I need to do, that's going to take care of itself. When I laid down and thought about where I saw myself being in school outside of football, it was SC."

Brady Hoke currently has 18 commitments for the 2013 class, a group that is rated No. 1 overall nationally by Scout.com.

Michigan presently has one running back in that class, four-star prospect DeVeon Smith (5-11, 210) from Howland (Ohio) High School.

Smith is rated as the 32nd-best running back in the country by Rivals.com.