Clark played quarterback and safety at Calera High School as a senior in 2013, accounting for more than 2,500 yards and 35 touchdowns. He made 76 tackles with 12 tackles for loss, two interceptions and four forced fumbles in 2012.

He registered 75 tackles and four pass breakups as a sophomore in 2011, when he also rushed the ball 43 times for 651 yards and five touchdowns while catching 48 passes for 488 yards and four scores. He was a member of the Alabama roster in the 2013 Alabama-Mississippi All-State Game.