Patriots RB Rex Burkhead ruled out with knee injury

PITTSBURGH -- New England Patriots running back Rex Burkhead was ruled out of Sunday's game against the Pittsburgh Steelers early in the third quarter after sustaining a knee injury.

Burkhead remained down after being tackled by Tyson Alualu on a 2-yard run, and while he walked off the field under his own power and into the medical tent along the sideline, it wasn't long before the club officially ruled him out of the game.

Burkhead shares lead running back duties with Dion Lewis, with James White coming into the game in more obvious passing situations. If Burkhead's injury keeps him out in the coming weeks, the team could elevate Mike Gillislee -- who signed to a two-year, $6.4 million contract in the offseason as a restricted free agent -- to the 46-man game-day roster. Gillislee has been inactive for the team's past six games.

A dual-threat option, Burkhead entered Sunday's game with 60 carries for 252 yards and four touchdowns, while adding 29 receptions for 249 yards with three touchdowns. He also plays on the kickoff coverage punt protection units.