There is a nice Mark Donnal story on Mlive.com . The story mentions how difficult it was for him not to play last year as he was holding his own against the starters.
The quote I liked to see was this:
Because of that, Donnal opted to attend both U-M summer sessions this offseason. He remained on campus, emulating last summer’s regiment of Nik Stauskas and Caris LeVert that was often cited for their breakout 2013-14 campaigns. Joined by Irvin, LeVert (who is recovering from injury) and sophomore point Derrick Walton Jr., Donnal logged added hours in the gym and on the court. The group visited with U-M strength and conditioning coach Jon Sanderson “nearly every day,” in Donnal’s estimation. Three days a week focused on weight lifting. Some days consisted primarily of stretching, agility drills or endurance training.
Donnal noted his biggest emphasis has been “developing my body and fine-tuning everything -- working on post moves and making sure my jumper is alright.”
It sounds like he is confident and ready to go.