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."