Martin doesn't have nearly as much upside as Harrington does, but he has been around quite a while and gives the Dolphins a better option than Cleo Lemon, who remains a project at this time.
The Cincinnati Bengals are in a similar position as the Dolphins in that they're looking for a backup behind their rehabilitating starter -- in their case Carson Palmer -- and Cincinnati also has expressed interest in both Harrington and Martin.
The Kansas City Chiefs also are players in the "Harrington sweepstakes" and it just might come down to which team is willing to give Detroit the best draft pick.
The Dolphins don't have picks right now in the second, fifth or sixth rounds, which is why working out a trade with Detroit has been a problem. Word is the Lions have gone from asking a late-round pick to a third- or fourth-round selection.