The team was concerned it could be a serious injury, but the MRI results showed otherwise, according to the source. Cromartie's status for Sunday's game against the Pittsburgh Steelers is uncertain.
On Thursday, Cromartie appeared for the first time on the post-practice report with a knee injury and "limited" participation. Coach Rex Ryan didn't provide any information other than what was on the report.
Although Cromartie appears to have avoided a serious setback, his injury is just the latest in a string of struggles for Jets cornerbacks this season.
Former starter Dee Milliner, a first-round pick, was demoted in Week 3 and later suffered a hamstring injury that has caused him to miss the past two games. He hasn't returned to practice and isn't expected to play Sunday against the winless Steelers.
Cromartie, coming off a Pro Bowl season, is one of the Jets' most important defenders because he often is assigned to the opponent's No. 1 receiver -- the job previously held by Darrelle Revis, who was traded this past offseason.
In three-plus seasons with the Jets, Cromartie never has missed a game due to injury.