updated 3:38 a.m. ET April 20, 2006

MIAMI - Detroit Lions quarterback Joey Harrington has decided to sign with the Miami Dolphins, his agent said Wednesday, giving the team a backup to new starter Daunte Culpepper.

With Culpepper facing an uncertain timetable in his recovery from a serious knee injury, Harrington might be Miami’s No. 1 quarterback when the season begins.

The Dolphins and Lions are expected to complete a trade soon, sending Harrington to Miami. The Lions decided a month ago not to retain Harrington, a starter during his four seasons in Detroit.

“I look forward to joining the Miami Dolphins whenever I am released or a trade is completed,” Harrington said in a statement from his agent, David Dunn. “The Dolphins are an ascending team with great coaching, and I can’t wait to get started.”

The Dolphins barely missed the playoffs last year after winning their final six games. Optimism about the 2006 season rose when Miami acquired Culpepper from Minnesota a month ago.

Gus Frerotte and Sage Rosenfels were the quarterbacks in Nick Saban’s first season as Miami coach last year.

Harrington, drafted No. 3 overall in 2002, was 18-37 as a starter with the Lions under three coaches: Marty Mornhinweg, Steve Mariucci and Dick Jauron. He threw 60 touchdown passes and 62 interceptions with the Lions, and his career quarterback rating is a modest 68.1.

“I learned so much in Detroit, and I will always value those relationships and that experience,” Harrington said. “At the same time, I am eager to get to work with my new team, whether that happens in a day, a week or a month.”

Special report Round-by-round recap, analysis, more

The Dolphins and Lions have been trying for two weeks to work out a trade for Harrington. Lions spokesman Bill Keenist said the team did not have a comment on the situation. Dolphins spokesman Harvey Greene didn’t return a call seeking comment.

Slide show   Week in Sports Pictures Pain on the skating rink, flying high on the hardwood, upsets on the football field, and more. more photos

The Lions are certain to part with Harrington before June 15, when he is due a $4 million bonus. He’ll likely be replaced by Jon Kitna or Josh McCown, both former starters who agreed to terms with Detroit last month.

MORE FROM NFL

NFL Section Front

Shaky state of the Steelers   PFTV: Patriots will prove devilish for Saints PFT’s Picks: Colts, Saints to finally taste defeat PFT: Giants' playoff hopes now in big trouble Pompei: Like it or not, Lions to stay on Thanksgiving   Slideshow: The Greatest traditions in sports   Vote: Do you watch the NFL on Thanksgiving? McDaniels’ trash talk strikes chord across NFL   PFTV: Browns could get No. 1 pick, but is that good?   Slideshow: Top plays from Week 12 NFL Section Front   Add NFL headlines to your news reader: