An MRI of Cromartie's left knee revealed a sprain, not a torn ACL, according to the team. He's listed as week-to-week and hasn't been ruled out of next Monday night's game against the Indianapolis Colts.
The Jets also announced that rookie linebacker Lorenzo Mauldin, who suffered a concussion Sunday after a frightening pileup, has been released from the hospital. There was no immediate word on when Mauldin will be able to play again.
Mauldin, wearing sunglasses, stopped by the Jets' facility and spoke with coach Todd Bowles, who received word late Sunday that there was no neck injury and no permanent damage.
"It was good to hear it wasn't as bad as [it looked]," Bowles said. "When you cart somebody off the field like that and they're not moving, immediately you think the worst. So to get that [news] was good."
Mauldin said in a tweet Monday afternoon that he would be fine.
In the aftermath of New York's season-opening 31-10 win over the Cleveland Browns, the Jets feared that Cromartie had suffered ligament damage after a noncontact injury in the second quarter. He was in such pain that he needed two trainers to help him off the field. After a brief examination on the sideline, he was carted to the locker room.
Cromartie was injured on a Johnny Manziel scramble but was about 20 yards away from the quarterback. Manziel ran to the right; Cromartie was covering a receiver on the left side of the field. His knee apparently buckled or twisted, and he crumpled to the turf.
Bowles said he was "very relieved" upon hearing the MRI results, acknowledging he thought it may have been a major injury. The coach was hesitant to put a timetable on Cromartie's return.
"I don't have an answer for that," Bowles said. "I don't know how he's going to feel from day to day. The doctors told me week-to-week. I haven't seen him run. Up until now, I'd say no [for the next game]. If he starts running later in the week and is feeling better, there's a chance he'll play."
Losing Cromartie for the season would have been a major setback for a team that devoted significant resources to upgrading its secondary. The Jets doled out $150 million in contracts last offseason, with Cromartie and Darrelle Revis -- reunited after a two-year separation -- the centerpieces of the rebuilding project.
Cromartie, 31, is one of the most durable players in the league; he has never missed a game due to an injury. He missed his final year at Florida State (2005) due to a torn ACL in the same knee.
Mauldin gave the Jets a scare, going down in the fourth quarter when his head got pinned beneath a pile of bodies. He rose to his feet but wobbled and collapsed to the turf. Players said he was unconscious. The training staff and emergency medical personnel moved him carefully to a spinal board, and an ambulance transported him to a local hospital.
About two hours after the game, the Jets announced that Mauldin had a concussion and that he was awake and had feeling in his extremities.