The defensive end says he made the choice before Clemson's regular-season finale with South Carolina and wanted to make it known so people would stop asking him about it.
Lawson leads the top-ranked Tigers with 10 sacks and 22 1/2 tackles for loss.
The Tigers (13-0) returned to practice Monday to prepare for No. 4 Oklahoma in the Orange Bowl on New Year's Eve.
Lawson has been a disruptive force for Clemson in a season in which the team lost eight starters on defense, including first-round NFL picks in defensive end Vic Beasley and linebacker Stephone Anthony.