Harrington had been an unrestricted free agent after serving as New Orleans' third quarterback for 12 games last season. But the Saints had said all along they wanted Harrington back and were just waiting until there was room under the salary cap.
Harrington, 30, was a first-round pick by Detroit in 2002. In seven NFL seasons, he has started 76 games while completing 1,459-of-2,538 passes for 14,683 yards with 79 touchdowns and 85 interceptions.
ESPN.com NFL blogger Pat Yasinskas covers the NFC South.