BOSTON (CBS) — The New England Patriots will be without running back Dion Lewis for the rest of the season, as an MRI on Monday revealed he has a torn ACL.

Lewis suffered the injury in the third quarter of Sunday’s win over the Washington Redskins.

Tough news out of Foxborough: #Patriots RB Dion Lewis out for the season with torn ACL per team source. — Jim McBride (@globejimmcbride) November 9, 2015

Though he was small in stature, Lewis was a big part of New England’s offensive success in the first half of the season. In seven games, Lewis rushed for 234 yards and two touchdowns on 49 carries, and was also a big factor in the pass game, catching 36 passes for 388 yards and two more touchdowns.

Before going down on Sunday, Lewis had four rushes and four receptions for a combined 53 yards against Washington.

“It’s such a physical game and tough to lose such a special player,” Tom Brady said after Sunday’s game.

Lewis had been the perfect replacement for Shane Vereen, who signed with the New York Giants in the offseason. The Patriots were so impressed with what Lewis brought to the team in the early parts of the season that he was signed to a two-year extension in early October.

LeGarrette Blount finished out Sunday’s game for the Patriots, rushing for 129 yards and a touchdown on 29 carries, and figures to get more carries with Lewis out. As far as replacing the Lewis’ pass-catching in the offense, they could turn to 2014 fourth-round pick James White, who was inactive for Sunday’s game. Brandon Bolden, who caught an 18-yard touchdown in the fourth quarter on Sunday, will also likely have a bigger role on offense in Lewis’ absence.