Both Harris and Moncrief were officially ruled out on Saturday, indicating they did not travel with the team to Miami. Harris had been listed as questionable due to an ankle injury, and Moncrief also was questionable with a thigh injury.
Sony Michel is expected to regain his role as the Patriots' starting running back with Harris sidelined. The 2018 first-round draft pick lost his starting role in Week 4 when he was placed on injured reserve. In the last two games, Michel has tallied 57 yards on 17 carries.
The Patriots also won't have Julian Edelman back in the mix on Sunday as the veteran wide receiver reportedly will not be activated off injured reserve for the matchup.
Sunday's Patriots-Dolphins game is set to kick off at 1 p.m. ET.