In December 2003, following a Lions 45–17 loss to the Kansas City Chiefs at Arrowhead Stadium, Millen came under fire after a postgame incident with former Lions and then-Chiefs wide receiver Johnnie Morton. Millen tried to congratulate some of the Chiefs players near the Chiefs locker room, when he confronted Morton, who claimed that he wasn't going to say anything to Millen. When he walked by him, Millen said, "Hey Johnnie." Morton ignored him, and then Millen replied, "Nice talking to you", and Morton replied "Kiss my ass." That's when Millen shouted, "You faggot! Yeah, you heard me. You faggot!" at Morton, which was heard by a member of the Chiefs public-relations staff and a "Kansas City Star" columnist. Millen apologized for the incident, and after he was informed of Millen's remarks, Morton replied, "I apologize for what I said, but I never expected anything like that. What he said is demeaning and bigoted." There had been bad blood between the two since Morton was released by the Lions after the 2001 season, and Morton felt like Millen "tossed him aside."