Ridley is recovering from ACL knee surgery and was limited to six games last year with the Patriots.
His best season was in 2012, when he ran for 1,263 yards and 12 touchdowns. The Patriots took him in the third round of the 2011 draft.
Miller carried the bulk of the load for Miami last year after Moreno played in only three games because of injuries. Moreno is now a free agent.
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