Early in the third quarter, Jets running back Shonn Greene left the field and headed to the locker room after climbing out of a pile of Colts defenders. CBS color man Phil Simms speculated that the injury was to Greene's thigh, but there's been no official word yet.
As soon as more information is being made available, we'll pass along an update.
UPDATE: This is from NBC Sports.
Shonn Greene exited Sunday's AFC Championship at the start of the third quarter with an undisclosed injury.
Greene appeared to suffer a stinger or rib injury. Injured on New York's first second-half possession, Greene seemingly had a difficult time inhaling and exhaling as he made his way to the locker room. CBS reports that Greene didn't look good after coming out of the X-ray room and is out "for the foreseeable future." Thomas Jones is handling every-down back duties.