The Gophers already lost some experience at the running back position for their spring practices that just began on Thursday. 

Donnell Kirkwood, who racked up 229 rushing yards in 2011, has the most yards of any returning RB on the roster this spring. But, he re-injured a hamstring that has given him problems in the past, the Star Tribune reported. 

"He's a good kid and he's worked so hard, I really feel bad for him," coach Jerry Kill told the Star Tribune. "He's had hamstring trouble since he's been here." 

Kirkwood, a sophomore from Delray Beach, Fla. was a redshirt-freshman last season, yet managed to play at least a little in every game. 

Fellow running backs David Cobb, junior college transfer James Gillum and redshirt freshman Devon Wright will pick up the slack. Kill said he hopes Kirkwood will be healthy enough for individual drills before the end of spring practice, which is April 21.