Jets quarterback Sam Darnold looks to pass during the second half...

Jets quarterback Sam Darnold looks to pass during the second half of a game against the Bills at MetLife Stadium on Sunday. Credit: Lee S. Weissman

FLORHAM PARK, N.J. — Sam Darnold has mononucleosis and is expected to miss multiple games, Jets coach Adam Gase said Thursday.

The Jets sent their starting quarterback home from practice Wednesday with what they thought was strep throat. But they learned Wednesday night that Darnold has mono. Gase was among the people who went to Darnold’s place to deliver the bad news.

Trevor Siemian will start in place of Darnold Monday night against the Browns, and likely Week 3 at New England. Gase didn’t officially rule Darnold out for next week, but he said “it looks like it.” Luke Falk will be elevated from the practice squad to be the Jets’ backup quarterback.

The Jets have a bye in Week 4. Gase hopes Darnold can return for Week 5 at the Eagles.

“Good thing we got the early bye week,” Gase said. 

Darnold played in Sunday’s 17-16 loss to the Bills. By all accounts he seemed fine on Monday when the team met and watched film. But Gase said Darnold “didn’t look good” when he came to practice Wednesday.

The Jets sent Darnold home because he was contagious and they didn’t want to infect the rest of the team.

According to Gase, Darnold was concerned that he had lost some weight, roughly five pounds. The medical staff did additional tests because the antibiotics they had given Darnold weren’t working and discovered he had mono. Gase said Darnold knew his condition was more serious when Gase and offensive coordinator Dowell Loggains accompanied trainer Dave Zuffelato to see Darnold Wednesday night.

“They’re still going through and making sure they’re doing all these tests on him,” Gase said. “I know his biggest concern is weight loss. That was something that was alarming to him that he lost some weight the last couple of days.

“Right away he went into, ‘I have to get some meals over here,’ because he can’t be in the building right now. ‘I need to get meals over here, I need to make sure that I’m getting enough of what I need to keep my weight.’ He went right into, ‘How do I maintain?’ ”

Darnold could continue to lose weight and strength to the point that even when he’s ready to come back, he may not be 100 percent, and fatigue could be an issue. But Gase felt good about how Darnold planned to attack this.

“He went right into, ‘Where’s my solutions?’ ” Gase said. “He moved past the bad news and went into, ‘How am I going to get myself ready for when I am able to return to where I’m not in a bad place?’ ”

It’s a major blow to the Jets, who are dealing with numerous health issues to key players.

Starting inside linebacker Avery Williamson (torn ACL) and Quincy Enunwa (neck) are out for the season. Running back Le’Veon Bell underwent an MRI on his sore shoulder Thursday. Middle linebacker C.J. Mosley (groin), defensive lineman Quinnen Williams (ankle) and newly acquired receiver Demaryius Thomas (hamstring) didn’t practice Thursday.

Gase gathered the team before practice Thursday to tell them about Darnold and let everyone know what’s expected of them this week.

“I told them how our next-man up philosophy does not waver,” Gase said. “It’s about everybody doing their job. That’s why Trevor’s here. We signed Trevor specifically because his 24 starts over his career, has a winning record, has lot of experience, has been on winning ball clubs, he has the respect of the locker room. The reaction I got and the way the guys looked was, ‘Let’s go.’ ”

Siemian will be playing his first NFL game since 2017. He served as Kirk Cousins’ backup in Minnesota last year and never took a snap. But Siemian played 26 games with Denver the prior three seasons, completing 495 of 835 passes (59.3 percent) for 5,686 yards, 30 touchdowns and 24 interceptions. He was 13-11 as a starter in two seasons for the Broncos.

Gase has confidence in Siemian and the rest of his players. He said it’s important for himself and the Jets’ hierarchy to remain focused, strong and positive in the face of adversity.

“It starts with me and my attitude,” Gase said. “What’s our attitude going to be? Is it going to be woe is me or sky is falling? Or is it going to be this is a challenge we’re going to embrace and guys being tighter in the locker room and everybody coming together and doing their job as well as they can to help us win?

“I think we’ll look back at this is and this is going to be a good thing for us. It’s going to bring our locker room even tighter.”

What is mono?

Mononucleosis is an infectious illness that’s sometimes called mono or “the kissing disease.” While you can get the virus that causes it through kissing, you can also get it in other ways like sharing drinks or utensils. Mono isn’t usually a serious illness, but it can lead to complications that in some cases make the disease more dangerous.

Causes

In general, the Epstein-Barr virus (EBV) is what causes mono. It’s a common virus that many people are exposed to as kids. But even if you’re exposed to EBV, it’s not guaranteed that you’ll get mono. It’s possible to be infected with EBV and carry it in your body for your entire life without ever having symptoms of mono.

Symptoms

Fever, fatigue, sore throat, swollen lymph nodes, sore muscles and a loss of appetite.

Treatment

Rest with a gradual return to normal activity.

Recovery time

Most people start to recover from mononucleosis within two weeks, though some symptoms, such as fatigue, can take 3-4 weeks or even longer to go away.

Source: WebMD

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