Harrison's 2010 season was marred by committing several penalties and fouls. He was fined for the hits that were deemed to be illegal by referees and the NFL. In Week 2, Harrison was fined for flipping Vince Young of the Titans. On October 17, he knocked out two Browns wide receivers; Mohammed Massaquoi, and his former college teammate, Josh Cribbs. On Halloween against the Saints, he hit quarterback Drew Brees late from behind. Against the Raiders, he hit another QB, Jason Campbell. The following week at Buffalo, another incident occurred when Ryan Fitzpatrick had thrown a complete pass to David Nelson, Harrison came out of the line and speared Fitzpatrick. Harrison was fined an estimated $120,000 in total.