Jets RB/KR Braelon Allen (knee) out 8-12 weeks

New York Jets running back/kick returner Braelon Allen will miss eight-to-12 weeks with an MCL sprain, head coach Aaron Glenn said Friday.

Allen was placed on injured reserve Thursday, three days after he sustained the injury in New York's 27-21 loss to the Miami Dolphins.

Allen, 21, was hurt on a kickoff return in the second quarter after losing his first career fumble in the first quarter.

"There are two different ways he can go about it," Glenn said of Allen's plans for recovery. "He could actually rehab this or he could have surgery and get it cleaned up. The rehab time would be exactly the same. That'll be a decision he and his agent have to make, and I'm not making that decision for him."

Isaiah Davis has been used as the third-down back, but his role might expand to helping out behind starter Breece Hall on Sunday when the Jets (0-4) host the Dallas Cowboys (1-2-1).

The Jets also signed running back Khalil Herbert, who has return experience. He was cut from the Seahawks' practice squad on Wednesday.

Allen has 18 carries for 76 yards this season. He's averaging 25 yards on four kickoff returns.