Justin Forsett has broken right arm

BALTIMORE -- Ravens running back Justin Forsett broke his right arm in the first quarter of Baltimore's 16-13 victory against the Rams.

Forsett, the NFL's 10th-leading rusher, was slammed to the ground by Rams defensive tackle Aaron Donald with 4:50 left in the first quarter. He was helped off the field with his right arm in an air cast.

The Ravens now are down to their third running back,rookie fourth-round pickBuck Allen, after losing Forsett and backup running back Lorenzo Taliaferro, who was placed on IR on Oct. 14.

Forsett had a productive start Sunday, gaining 31 yards on his first three carries.

Forsett's injury wasn't even the biggest of the day for a wounded Ravens roster as quarterbackJoe Flaccotore the ACL and MCL in his left knee on the final drive of the game. Baltimore (3-7) had already lost leading receiverSteve Smith Sr.to a season-ending Achilles injury three weeks ago.

Forsett is one of six significant offensive player to go on injured reserve, joining Flacco, Smith, tight end Dennis Pitta, wide receiver Breshad Perriman and center Jeremy Zuttah.