Kirby, who sat out last season, also has returned kickoffs during his NFL career, but he's never been a workhorse back. So consider him a long shot, at best.
The other player who worked out was former Jaguars and Texans back Stacey Mack. Remember, Mack rushed for 87 yards against the Dolphins in Houston's stunning victory at Pro Player Stadium in last year's opener.
There could be other running backs coming in for workouts, one of them being former Chicago and Houston back James Allen.
And here's another interesting name: Robert Edwards. He contacted the Dolphins earlier this week asking for another shot. At this point, though, there's no indication they'll bring him in for a workout.
As for trade possibilities, Colts general manager Bill Polian told the Indianapolis Star — in no uncertain terms — that Edgerrin James would not be traded.
Other suggested deals have included the Dolphins trying to land either Chicago starter Anthony Thomas or backups Onterrio Smith from Minnesota or Najeh Davenport from Green Bay.