Posted by ESPN.com's Adam Rittenberg
Evans, a junior, started one game last fall and appeared in 10 contests but played mainly on special teams. He recorded four tackles in 2008.
"I've had three defensive coordinators in three years and I like the coaches but I'm not sure I fit this system," Evans said. "The coaches didn't understand but I have to do what's best for my future."
The Richmond, Va., native hopes to transfer to an ACC or SEC school.
Helmuth, also a junior, appeared in 14 games at Michigan, mostly on special teams and as a fullback in 2007. He played sparingly last fall.
Though Evans and Helmuth depart, Michigan got some good news as cornerback recruit J.T. Turner has been academically cleared and will practice with the team Thursday. Turner was ranked as the nation's 21st best athlete in the 2009 class by ESPN's Scouts Inc. and could contribute early in his career.
"He wasn't here for summer school so he didn't get as much done as some of the other freshmen, so he's going to be a little bit behind," head coach Rich Rodriguez said. "But he's a skillful guy and with our lack of depth and the needs we have in the secondary, if he can learn quickly he can help us. But I probably won't know that for another week or two."
Michigan is still waiting on the eligibility status of safety recruit Adrian Witty. Rodriguez also could learn Thursday whether Jason Forcier, the one-time Wolverines quarterback and the older brother of freshman signal caller Tate Forcier, will be able to join the team this year.