A Houston-area prep, he wanted to attend Texas A&M, but an unfulfilled academic requirement left him without a four-year option. Accepted an offer to play from Blinn Junior College (Texas). While in high school in 2008, he was charged with misdemeanor assault and criminal mischief when he was part of a group that fired paintball guns at bystanders from a moving truck. Appeared in 10 games for Blinn in 2010 and ran 160 times for 1,169 yards (7.3-yard average) and 17 touchdowns with eight receptions for 90 yards (11.3) and no touchdowns. Was a second-team NJCAA All-America selection in 2011 after totaling 174 rushes for 1,052 yards (6.0) and 16 touchdowns and 14 catches for 171 yards and two touchdowns, earning him an invitation from Arizona State. Despite not starting any games for ASU in 2012, he scored 11 rushing touchdowns and led FBS running backs with eight receiving TDs. Rushed 103 times for 679 yards (6.6) and 11 touchdowns and caught 41 passes for 425 yards and eight touchdowns. In late December, a close friend of Grice was reportedly shot and killed over a new pair of Air Jordans; eight days later, Grice returned to the Sun Devils for their Kraft Fight Hunger Bowl appearance against Navy and was named the game's MVP, rushing 14 times for 159 yards and two touchdowns. Was a Hornung Award Finalist in 2013, totaling 191 carries for 996 yards and 14 touchdowns and 50 catches for 438 yards and six touchdowns; he also returned 21 kickoffs for 507 yards and no touchdowns (was the only player in the country to surpass the 400-yard mark in each of those categories). Averaged 176.5 all-purpose yards per game, ranking third in FBS. Missed the final three games with a left leg injury. Had 39 touchdowns in his 24-game ASU career and did not lose a fumble in 406 touches.
Good balance and body control. Has loose ankles and very good lateral agility. Explosive one-cut ability. Displays vision and elusiveness in the open field. Sees the cutback and weaves in and out of traffic. Has some wiggle to shake tacklers in space. Good receiver -- bursts into routes, adjusts to passes and has soft hands. Fumbled only once the last two seasons. Blue-collar work ethic. Solid character.
Has a lean, narrow frame. Needs to bulk up and get stronger. Not equipped to pound between the tackles -- gets tall inside and doesn't push the pile (soft on contact). Weak tackle-breaker who cannot be counted on for yards after contact. Can become a more disciplined route runner. Questionable awareness in pass protection. Statistical production belies inconsistency.
Fluid perimeter runner/receiver with playmaking ability, though his game is rough around the edges, requiring more polish and attention to detail. Profiles as a third-down/change-of-pace back, but his football intelligence has to catch up with his physical gifts in order to earn trust he can handle the role.