Former Redskins defensive lineman Albert Haynesworth went on radio to attack his former boss last week, telling Tennessee Sports Radio: "Shanahan is conniving and all 'me, me, me'. Nothing is ever going to be the head coach's fault. Ever. He will run RG3 (Robert Griffin III) into the ground."
Shanahan has now hit back, laying into Haynesworth, who was a $100 million free agent when he signed with the franchise in 2009.
"When you don't get along with somebody as a head coach or an assistant coach, it usually falls into one of three areas: lazy, lack of passion, and a lot of times lack of character," Shanahan told Fox Sports. "And Haynesworth fits all three.
"You usually take the high road as much as you can, I usually do. But he's been talking quite a bit, over the last couple of years, so I thought at least I'd be honest with you guys and tell you how I feel about him."
Haynesworth has been without a team since his release from the Tampa Bay Buccaneers in February 2012.