Northwestern has suspended running back Venric Mark for the first two games for violating a team policy.

The school said Friday that Mark will miss home games against California on Aug. 30 and Northern Illinois on Sept. 6.

Mark was granted a medical hardship waiver by the Big Ten and allowed to return for a fifth year after missing most of last season with a broken ankle. He was limited to three games in 2013 after rushing for 1,366 yards and 12 touchdowns as a junior. He ranks fourth all-time at Northwestern with 4,271 all-purpose yards.

In a statement, Mark says he ''made a mistake'' and ''let my teammates down.''