While with the New England Patriots during the 2014 season, Gray averaged 4.6 yards per carry with 412 rushing yards five touchdowns. However, four of those touchdowns and 201 of those yards came in one game against the Indianapolis Colts in Week 11.
According to Barry Jackson of the Miami Herald, Gray's agent, Sean Stellato, said the Dolphins did not discuss when or if they would promote Gray from practice squad to 53-man roster.
This is Gray's second stint in Miami as he was previously on the Dolphins' practice squad in 2012. He worked out for the Tennesee Titans this week but ultimately decided that Miami was the best fit for him.