Lee, who did not appear in Saturday's game, played in 36 games during his career.
According to The Tennessean, Greenstone's job is to keep players away from the sideline to avoid getting penalized.
Greenstone recovered somewhat from the first punch, but Lee's fist returned nearly immediately, sending the couch down to the ground.
Uber rant caught on camera; fired Texas prosecutor speaks
According to the Dallas Morning News , the 32-year-old prosecutor was sacked on Monday following a "thorough investigation". A former Dallas County prosecutor came to Warner's defense online. "There's two sides to every event", Schulte tweeted.
The Tigers offense was on the field at the time as Greenstone walked down the sideline telling players to move back if they were too close. "We are committed to supporting the coach who was personally affected and our concern now is with him". Before he was expelled, Lee was in his fourth year at Tennessee State as a criminal justice major. Greenstone twice in the head during last weekend's game against the Southest Missouri State Redhawks at Hale Stadium in Nashville.
University officials were informed and as of 10:30 a.m. on Monday the student has been withdrawn from school.
The Tennessean notes Greenstone is meeting with police today to decide whether he wants to press charges against Lee.