The Jets intend to place Allen (knee) on injured reserve Thursday, Rich Cimini of ESPN.com reports.
Allen is recovering from an MCL sprain sustained in Monday's 27-21 loss to the Dolphins, and while a formal timeline for his return won't be established until a decision is made whether he'll require surgery, the 21-year-old will be sidelined for at least the Jets' next four games. New York could add another running back to its roster in a corresponding move when Allen is officially placed on IR, but as it stands, Isaiah Davis and Kene Nwangwu (hamstring) are the backfield options behind starter Breece Hall.