The highlight of Monday’s Jets practice was Sam Darnold jogging onto the field while the rest of the team was stretching. It went downhill after that.

The Jets had a real sloppy practice. The offense looked out of synch and both sides of the ball continue to commit too many penalties. Referees called nine penalties during the practice, six on the offense. That led to a lot of penalty push-ups for the Jets.

“There was effort but it was sloppy,” Jets coach Todd Bowles said. “To be expected, new installs going in one day to the next and the third or fourth practice, it was sloppy but that’s what we’re practicing for.”

It is not unusual for things to look a bit choppy early in training camp. The players are getting fed the playbook in chunks and then having to execute those plays on the field. It can take a week or so before practices begin to look crisp.

“That’s something that we’ll talk about and have to clean up,” defensive end Leonard Williams said of the ugly practice. “It kind of looked sloppy but you never really know until you watch film. There were a few penalties. That’s one thing that’s sloppy and you don’t need film to watch that. That’s definitely something we could pick up on is a little less penalties. A few days ago we kind of ended practice with penalties and today we started practice with penalties. Something we need to work on is being consistent. I think that’s just something that comes with practice.”

Penalties have been an issue every day of training camp. The Jets have had at least six penalties each day.

“We started training camp with installs and physical play. It’s going to be part of the early process,” Bowles said of the flags. “As training camp goes on, it will diminish.”

Williams has had a strong start to training camp. He seems to make a play in the offensive backfield every day.

“It’s going great,” Williams said. “I haven’t had any MEs — mental errors. I’ve been running to the ball. I’ve been winning my one-on-ones.”

The Jets have their first day off of training camp Tuesday.

Jermaine Kearse had the catch of the day on a bomb from Josh McCown down the sideline during one-on-one passing drills. He was covered by Terrell Sinkfield and went up to grab the pass. After landing on the ground he jumped up and celebrated by throwing the ball high in the air.

While all of the attention was on Darnold signing Monday, his fellow rookies also have impressed. Defensive lineman Nathan Shepherd, tight end Chris Herndon, defensive lineman Folorunso Fatukasi and cornerback Parry Nickerson are all getting a lot of work, some with the starters.

On the first day, Darnold looked … rusty. He threw an interception off a tipped pass and looked out of synch. It is understandable for someone who has not been in a meeting yet. He did throw two touchdowns during a red-zone period. It was not a good day for Teddy Bridgewater or McCown, either, who both looked shaky.

Right tackle Brandon Shell left practice with an unknown injury. Bowles said he got “nicked.” … Defensive lineman Xavier Cooper (strain), safety Brandon Bryant (soreness) and safety Kacy Rodgers II (soreness) did not practice for the second straight day.