Geno Smith's hopes for a breakout season with the New York Jets took a major blow -- to the jaw.

The quarterback will be sidelined at least 6-10 weeks with a broken jaw after being punched by teammate Ikemefuna Enemkpali in the locker room Tuesday morning. Smith, entering his third season, will require surgery to repair the injuries. He hadn't yet undergone the procedure as of late Tuesday afternoon.

"It had nothing to do with football," coach Todd Bowles said. "It was something very childish, and he got cold-cocked, sucker-punched -- whatever you want to call it -- in the jaw."

Bowles made the stunning announcement in an impromptu news conference before training camp practice was scheduled to start. Enemkpali, an outside linebacker in his second season, was immediately released by the Jets.

"It was something very childish, that sixth-graders could have talked about," Bowles said. "It had no reason for happening."

Neither Bowles nor a small handful of players made available to the media would go into detail about the incident, or if they knew what sparked it.

"This isn't a UFC match," guard Willie Colon said. "We're football players, not fighters."

Added cornerback Darrelle Revis: "I hold both of them responsible. ... But at the same time, you've got to move forward."

Smith, who was having a good training camp, will be sidelined for the rest of the summer and likely for the first few games of the season. The regular-season opener at home against Cleveland on Sept. 13 is five weeks away.

"Depending on how surgery goes, we'll see where we go from there," Bowles said.

Smith took to Instagram and posted a picture of himself sitting in a car -- mouth closed and looking stern -- and a simple message: "ILL BE BACK."

In a statement issued to The Associated Press by his agent, Enemkpali apologized to the team and fans.

"Geno and I let our frustration get the best of us, but I should have just walked away from the situation," Enemkpali said. "I deeply regret and apologize for my actions. It was never my intention to harm anyone. I appreciate the opportunity I had with the Jets."

Bowles said the Jets could add another quarterback, but veteran Ryan Fitzpatrick will assume the starting job. Bryce Petty, a fourth-round pick this year out of Baylor, and undrafted free agent Jake Heaps out of Miami are the Jets' other remaining quarterbacks.

Bowles spoke again after practice and wouldn't commit to Fitzpatrick for the rest of the season or to Smith reclaiming his job when he's healthy, but indicated that a player could lose his starting spot due to injury.

"If the other guy is playing well and the boat is going right and there are no waves and everything is going and we're 4, 5, 6, 7-and-0," Bowles said, "yeah, you're not coming back to start."

Bowles, in his first season as coach, dealt with the news last month that star defensive lineman Sheldon Richardson was suspended four games by the NFL for violating the league's substance abuse policy and then was charged with resisting arrest after a high-speed road race in Missouri 12 days later. Richardson could face additional discipline by the league for violation of the personal conduct policy once the legal process plays out.

Bowles and the Jets players insisted that there is no deep-rooted issue in the locker room that requires a change in culture, and this was an isolated incident.

"Well, this is a first for me," said center Nick Mangold, entering his 10th season. "The biggest thing we need to look at is to make sure it doesn't happen again."

Bowles spoke for about 2 minutes before heading to a meeting and then practice, but was clearly angered by the situation.

"The team knows this is something we don't tolerate, something we can't stand," Bowles said. "You don't walk up to another man and punch him in the face."

Smith has 34 interceptions and 41 total turnovers in his first two seasons, but new offensive coordinator Chan Gailey was impressed with his progress this summer. Smith threw the first two interceptions of camp on Monday, an impressive stretch that had the quarterback and coaches thinking positively about his prospects for the upcoming season.

Enemkpali had three tackles in six games last season after being taken in the sixth round out of Louisiana Tech. This is not the first time Enemkpali, from Pflugerville, Texas, has been in trouble for fighting. He was suspended from the Louisiana Tech team in 2011 after being arrested for an off-campus incident in which he was booked with disturbing the peace and battery of a police officer.

To replace Enemkpali on the roster, the Jets signed cornerback Javier Arenas, who has played five NFL seasons with Kansas City, Arizona and Atlanta.

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