Harrington started 55 games, throwing for 10,242 yards with 60 touchdowns and 62 interceptions and a mediocre 68.1 passer rating.
He will be replaced by Jon Kitna or Josh McCown, both former starters who agreed to terms in the last week. The Lions already have under contract former Tampa Bay and Arizona starter Shaun King and second-year man Dan Orlovsky.
Harrington would have received a $4 million bonus if he was on the roster June 15.
Coach explains on Culpepper Minnesota Vikings coach Brad Childress says he saw a little of Terrell Owens in Daunte Culpepper. That was enough for him.
''It just became a deal where I didn't feel like it was the team, I felt like it was 'me,' " Childress said about Culpepper. ''I went through a big 'me' situation last year with a guy who was all about 'me.' "
While still the offensive coordinator at Philadelphia, Childress clashed with Owens during training camp, the precursor to the mercurial receiver's high-profile exile from the Eagles.
Shortly after replacing Mike Tice as the coach in Minnesota, Childress again found himself not seeing eye-to-eye with one of the team's marquee players.
Culpepper refused to rehab his severely injured right knee in Minnesota, preferring to remain at home in Florida. He also asked for a raise and was hesitant to meet with Childress and the new coaching staff to start examining the team's new offense.
With neither side budging, the Vikings shipped Culpepper to Miami last week for a second-round pick, days after Culpepper requested to be traded or released.
