Coleman attended J. J. Pearce High School in Richardson, Texas, where he was a three-sport star in football, basketball and track. In football, he excelled as a rusher, receiver and returner under head coach Randy Robertson and was named first-team 2011 All-Area by The Dallas Morning News SportsDay (as WR/RB/QB) and earned 2011 first-team Class 4A All-State and District 10-4A MVP honors as a wide receiver. As a sophomore, he totaled 707 yards and 10 touchdowns on 91 rushes as well as 19 receptions for 229 yards and one more score, earning second-team All-District 10-4A honors. He had 69 receptions for 1,003 yards and 11 touchdowns as well as 97 carries for 426 yards and 13 touchdowns as junior in 2010; he also made two interceptions at cornerback en route to 2010 All-District 10-4A honors. As a senior in 2011, he totaled 69 receptions for 932 yards and 11 touchdowns, 567 yards and 15 touchdowns on 84 rushes and threw for 106 yards on 5-of-6 passing. In his final three seasons, Coleman amassed 3,864 all-purpose yards and 61 touchdowns. Following his senior season, he was selected to play for the 2012 U. S. Under-19 National Football Team in the February International Bowl (formerly known as Team USA vs. The World).