Kwon Alexander raged through his first New York Jets practice Monday like a tornado. And that bolt of energy continued when the linebacker spoke with reporters for the first time since joining the Jets last Friday.

“It felt legendary to be out there, to get back under my feet, be out there with the team,” Alexander enthused. “I enjoyed it.”

Alexander signed as a free agent with the Jets last week after a two-month courtship to provide veteran depth and leadership. He worked on the side for two days and then was a surprise participant in the first practice with pads and hitting Monday.

“They were wondering if I was going to be ready, and I did all the drills and stuff,” Alexander said. “I told them to ramp it up a little bit more. So, I was ready to go.”

Alexander, who turns 28 on Thursday, made plays all over the field, including a big-time hit on running back Ty Johnson. His trademark trash talking was in mid-season form.

“I can add a lot to the defense, just me going out there being myself, leadership, bringing energy, bringing guys along, playing fast, playing with that dog and bringing everybody together,” he explained. “That’s me.”

Defensive coordinator Jeff Ulbrich said he was surprised at what terrific shape Alexander is in. He also was thrilled with the enthusiasm Alexander brings to every drill and play.

“He’s awesome,” Ulbrich said. “He’s got this infectious energy about himself, he’s got an edge to him, he’s got the ability to elevate people around him. So, to get that type of person in the building is awesome. It will make us better in practice. It will make us better in meetings. And it will ultimately make us better on Sundays.”

Alexander said he wasn’t told what his role is, but it’s expected he’ll play often alongside the Jets top linebackers, C.J. Mosley and Quincy Williams, especially in passing situations. He added that any role is good with him because of his relationship with Jets coach Robert Saleh, his defensive coordinator with the San Francisco 49ers for two seasons.

Saleh said he’s equally happy the 2017 Pro Bowler chose to sign with the Jets instead of his other suitors, the Giants and Saints.

“He’s in great shape. He’s got great recall of what we did in San Francisco,” Saleh said. “He’s a quick learner, really instinctual. He made a play in that last period (at practice) and he did what Kwon does, made sure that the other side of the ball knew about it and brought everybody to life. He’s a pleasure to be around. He’s A-plus.”

Now he just needs to stay healthy. Alexander has played more than 12 games once in seven NFL seasons because of injury.

But when healthy, he’s going to bring it. Just as he did Monday.