The Miami Dolphins placed veteran defensive tackle Earl Mitchell on injured reserve Tuesday and signed linebacker Donald Butler after working him out earlier in the day.
Mitchell missed all of training camp this summer with a calf injury and returned last Sunday to play in the regular-season opener against the Seattle Seahawks. He participated in 15 snaps and recorded one tackle.
The Dolphins will lean heavily on second-year defensive tackle Jordan Phillips to start opposite Ndamukong Suh. Phillips played well in Week 1, recording four tackles and a half-sack against Seattle in 49 snaps.
Butler played the last five seasons for the San Diego Chargers, and he had 43 tackles in 2015. He was with the Arizona Cardinals in training camp but was released by the team before the season began.
Miami (0-1) will travel to face the New England Patriots (1-0) on Sunday.
