Enunwa, injured in a noncontact drill on Saturday night at MetLife Stadium, faces a six- to nine-month rehab. The Jets don't consider it career-threatening.
"[The doctors] said it wasn't," coach Todd Bowles said Monday after practice. "Going forward, we'll see. They said he should come out of it OK."
Enunwa, the only receiver on the Jets' roster with 1,000 career receiving yards (1,172), missed minicamp in June because of a similar injury. The condition was "treatable" at the time, according to Bowles, who said Enunwa was deemed healthy at the start of training camp.
"He was doing fine," Bowles said. "When he fell the other night, it flared up."
On Saturday night, Enunwa dropped a pass from Christian Hackenberg during 7-on-7 drills when he took a step and fell to the turf face-first despite being untouched. He got up slowly, then crumpled to the ground and stayed down for several minutes.
They were counting on Enunwa to be their No. 1 receiver. Now Robby Anderson will move into that role, with Jalin Marshall and Charone Peake the next two in the pecking order. Marshall faces a four-game suspension for violating the NFL's performance-enhancing drug policy.
Statistically, the most accomplished receiver on the roster is Marquess Wilson (777 career yards), but he's considered on the bubble.
"Obviously, they have to get some experience and get some reps, but they're talented," Bowles said of his young receivers. "They just have to learn and get caught up to speed."
Bowles said the Jets haven't decided if they will add a veteran to the current group.
"We've got a lot of young guys we're trying to develop," he said. "If there's something out there that catches our eye, we'll sign him. If not, we'll stay with the guys we've got. All options are open."