He played college football for the Wisconsin Badgers and was signed by the Pittsburgh Steelers as an undrafted free agent after the 2011 NFL draft.

A 4-star recruit,[1] he committed to Wisconsin on national signing day after declining offers from Tennessee, Ohio State, Nebraska, and Iowa.

[1] Clay attended summer school to complete the required course work, then rejoined his teammates and began practicing with the Badgers.

As a redshirt freshman in 2008, Clay saw his first action on the field against the University of Akron, where he posted 71 yards and his first collegiate touchdown on just 12 carries.

He finished the season second on the team and seventh in the Big Ten Conference in rushing with 884 yards on 155 carries and nine touchdowns.

Clay was named one of three finalists for the 2010 Doak Walker Award, which is given annually to the nation's top running back.