New England Patriots RB Dion Lewis may need another knee surgery

New England Patriots running back Dion Lewis will need a second knee surgery to repair his torn ACL, a league source told the Boston Globe's Jim McBride.

The timetable for Lewis' return is uncertain, according to the report. Lewis tore his left ACL last Nov. 8 against the Washington Redskins.

Lewis participated in one session of organized team activities this spring but began training camp on the physically unable to perform list.

Lewis joined the Patriots on a futures contract in December 2014, and was a breakout star in seven games early last season with 622 yards from scrimmage and four touchdowns. He rushed 49 times for 234 yards and caught 36 passes for 388 yards before suffering the season-ending knee injury.

The Patriots' backfield includes LeGarrette Blount, James White, Brandon Bolden, Donald Brown and James Develin.