OSU said it made the moves after it had investigated allegations that Tressel knew of a banned financial relationship between six of his players and a Columbus, Ohio, tattoo parlor, but failed to report it.
The coach was suspended for the first two games of the 2011 season and fined $250,000.
Investigators said an e-mail written by Tressel showed he was aware of a deal between the players and Edward Rife, owner of Fine Line Ink Tattoos, to trade championship rings, jerseys and awards for cash and discounted tattoos.
The violations are serious and could result in harsher penalties from the NCAA, SI.com reported. For instance, Tressel could be charged with "failing to promote an atmosphere of compliance" and "failure to monitor" for not reporting what he knew to be infractions.
The penalties could include the forfeiture of all 12 of Ohio State's 2010 wins.