Ellison was a Rivals three-star prospect having been recruited by Oregon, Virginia Tech, California, Arizona St., amongst others.
Ellison caught 21 passes for 239 yards and three touchdowns for the Trojans last season.
Ellison, who played tight end and fullback at USC, was apparently not expecting to be selected. He told reporters who cover the Vikings that he was "pretty shocked" when team representatives called him on Saturday, the final day of the seven-round draft.
He was invited to 2012 NFL Combine as fullback.
NFL Comparison: Joel Dreessen, Houston Texans
"He is a reliable receiver who isn't afraid to go over the middle to take a hit. His route-running could use refinement, though, and he cannot stretch the field vertically. While he plays with aggressiveness, he doesn't play with power or violence."
"Ellison is a versatile option with experience lining up on the line of scrimmage as a tight end, in the backfield at fullback and out wide as a receiver. He is a quick athlete and is usually sure-handed as a receiver... Ellison will have his share of drops with inconsistent focus and too often tried running with the ball before the catch. He needs to play more disciplined and control in the moment."
"Ellison will get an opportunity to crack the starting lineup as lead blocker for Adrian Peterson and Toby Gerhart. He has flashed strength and toughness as a blocker, but needs to become more consistent to win the job."
"He is a strong and competitive runner after the catch, but lacks the speed to out-run tackling angles. Ellison is a good value as he has developmental potential, but is unlikely to become a starter."