As reporters were leaving the field Thursday after viewing the early portion of the Jets’ practice in Florham Park, defensive coordinator Gregg Williams offered a departing message:

“Mosley is going to practice,” Williams bellowed in headline fashion. “Mosley is going to practice.”

There might have been an expletive involved, but you can’t blame Williams for being excited that the Jets’ prized inside linebacker might be available to play Monday night against the unbeaten Patriots after injuring his groin in the season opener against the Bills.

In fact, C.J. Mosley isn’t waiting for coach Adam Gase to make an official announcement. Mosley made it himself after going through individual drills on Thursday.

“I’m playing Monday night,” Mosley said emphatically. “Unless I get hurt or something, I’m playing.”

That’s good news for the Jets (1-4). If you thought the offense was happy to see quarterback Sam Darnold return after missing four games with mono, the defense will be equally happy to have Mosley back in the lineup.

“He’s a four-time Pro Bowler,” said safety Jamal Adams. “We’re looking forward to getting him back out there.”

It would be a huge lift for the defense, just in time to face Tom Brady and the Patriots (6-0) at the Meadowlands. The Jets thought enough of Mosley to make the former Raven a captain in his first season after signing a five-year free-agent contract, which could be worth up to $85 million.

It looked like he was worth every penny during the first three quarters of the season opener at MetLife Stadium. Mosley helped forge a 16-0 lead by returning an interception for a touchdown and forcing a fumble that stopped a promising Bills drive.

With 4:04 left in the third quarter, he was sprinting stride for stride with Bills wide receiver John Brown and was in perfect position to break up a deep pass to the end zone. But he came up hobbling, and limped off the field. Without Mosley, the defense collapsed, and the Bills scored 17 unanswered points to claim a 17-16 win.

Mosley thought he would be back the next week, but Friday will be the first time he’ll take part in team drills since the injury.

“It was a long process,” he said. “After the fourth week and last week, I felt my body get better. The swelling went down. That was the main thing. At my position and what I do, it was affecting me cutting and changing direction, and I do that every single play. Once I got that mental block out of my head, it helped me get back on the field to test the limit.”

The defense has missed his leadership as well as his talent. The loss triggered a 0-4 start. Darnold returned last week to help the Jets beat the Cowboys 24-22 for the first win under Gase. Now Mosley is back for the rematch against the Patriots.

“It’s been annoying,” Mosley said of his injury. “You set a timetable and then you’re not ready. You feel like you’re having setbacks. You have to be patient. I know if I tried to get on the field the past couple of weeks, I would have only made it worse. For me, I have to stay focused and trust the process as far as therapy and training and eventually getting on the field. It finally paid off.”

The once ravaged linebacker group is gaining depth. Brandon Copeland returned last week after being suspended the first four games for testing positive for a banned substance. Now Mosley is back.

“It’s feels like I’m part of the team again,” Mosley said.

He doesn’t even mind the razzing he took from Williams.

“He talked a little smack three or four times,” Mosley said. “He always means well. He’s definitely a player’s coach. He’s going to get the best out of you because he’s going to give you his best.”

The Jets know they’ll get Mosley’s best, too.