"Upon returning to College Station last night, I had the opportunity to gather information and watch clips of one of our student assistant coaches initiating physical contact on two separate occasions with a West Virginia player," Sumlin said in the statement. "I am extremely disappointed and embarrassed, as his behavior reflected poorly on our program.
"On behalf of the Texas A&M football program, I want to apologize to [players] Darryl Worley and to Andrew Buie as well as to Coach Holgorsen and the West Virginia family for the inexcusable actions of the student assistant."
Richardson was caught by TV cameras striking Worley, a sophomore cornerback, and Buie, a junior running back, in the first half of Texas A&M's 45-37 victory. Sumlin told Richardson to remain in the locker room after halftime, and the Aggies released a statement at the beginning of the second half saying Sumlin was "aware" of Richardson's actions.
Richardson issued an apology on Twitter on Tuesday:
Worley also tweeted his reaction on Tuesday:
A former defensive end at A&M, Richardson had his playing career end as a freshman after suffering a cervical spine injury in 2012.
- Mike Fiammetta