Kwon Alexander did not take long to make his presence felt with the Jets.

Alexander participated in his first practice with the team Monday after signing with the team Friday. The linebacker had several big hits in the practice, the team’s first in pads, that had his teammates fired up.

“He’s in great shape,” Jets coach Robert Saleh said. “He’s got great recall of what we did in San Francisco. Obviously, there’s some new things that we’re doing here. He’s a quick learner, very instinctual. You guys saw he made a play in that last period and he did what Kwon does and made sure the other side of the ball knew about it. He brought everybody to life. He’s a pleasure to be around. He’s A-plus.”

Alexander said he was also talking to the Giants and Saints before picking the Jets. Alexander played for the 49ers in 2019 and 2020, when Saleh was their defensive coordinator, and cited his familiarity with the system and Saleh as big reasons why he picked the Jets.

Typically, the Jets have new players go through an acclimation period to get in shape if they have not been with another team. But the team was shocked to see the shape that Alexander was in when he ran through some conditioning drills over the weekend. Alexander said he worked hard to keep himself in playing shape so he’d be ready when he signed.

“I did everything I normally do,” Alexander said. “I’m going to always be ready. I’m not a guy to sit around, waiting on calls. I’m going to be prepared. When they had Day 1, I did my camp stuff, too. I did 50 reps. I was out here preparing. They were wondering, ‘Was I going to be ready?’ I did all the drills and stuff. I told them to ramp it up a little bit more. I was ready to go.”

Alexander, who turns 28 on Wednesday, had a productive second half of the season for the Saints last year after returning from an elbow injury. He made the Pro Bowl in 2017 and has established himself as a good player. Still, it took until late July for a team to sign him.

“I don’t know, man. That’s not my call,” Alexander said when asked if he was surprised to be a free agent for so long. “I just waited until my time. My time was a couple days ago. Now, I’m here to show what I got and do what I do best.”

The Jets love Alexander’s leadership abilities as well as his play. Alexander made plenty of noise on the field in his first practice, which he said he always does.

“That’s my thing,” Alexander said. “I really get the team going, having everybody out there be comfortable to be their self. That’s what I’m here to do. I’m going to be myself regardless. If I bring everybody with me, we’re going to do good things this year.”

Alexander said he will be fine with whatever role the Jets have for him. The Jets have C.J. Mosley and Quincy Williams as their top two inside linebackers. It would not be surprising to see Alexander lining up as the weakside linebacker with them in the base 4-3. The Jets also have Marcell Harris, Hamsah Nasirildeen and Jamien Sherwood at inside linebacker.

It seems like it might be hard to keep Alexander off the field.

“I’ve got a chip on my shoulder every time I come out there on that field,” he said. “I try to be the best I can be. For me, I’ve just [got] to get going. Once I get going, it’s going to be hard to stop me.”