Thomas, 24, was a fourth-round pick by the Arizona Cardinals in 2014. He saw action in two games last season, completing one of nine passes for 81 yards and a touchdown. Thomas made only one start before being benched in favor of Ryan Lindley. The Cardinals released Thomas Saturday.
Ajayi was a fifth-round pick in this year's draft. He missed much of training camp with a hamstring injury.
He returned in time for the Dolphins’ final preseason game, playing well until suffering a cracked rib. Ajayi had nine carries for 66 yards and two catches for 37 yards before his injury.
- Rohan Nadkarni