Ralph Vacchiano has more:
Kiwanuka complained of a stiff neck on Thursday, but practiced Friday - avoiding contact with his head and neck - after having an MRI performed Thursday night. He reported more stiffness after Friday's practice and was sent to the Hospital for Special Surgery in Manhattan where a CAT scan revealed the injury.
"It's disappointing," Kiwanuka said. "It just feels like a stiff neck. The pain is not intolerable but I want to make sure that I will be okay down the line. I have full trust in the medical staff and the trainers at the Giants. I'm going to do everything that is asked of me so when I'm cleared I'll be back and ready to go."
In a press release, the Giants said it's unclear when and how Kiwanuka suffered the injury.
Team doctors will monitor the injury and there is no immediate timetable for his recovery.