Jets’ Darnold out with mono

FLORHAM PARK, N.J. — A new coach, a marquee running back and a second-year quarterback brought renewed hope to the New York Jets this season. But one week in, that optimism has quickly diminished.

Sam Darnold has mononucleosis and will not play Monday night against the Cleveland Browns ( 0- 1), coach Adam Gase announced Thursday. There is no timetable for his return.

Darnold had received a diagnosis of strep throat Tuesday night, but further tests revealed he had mono. Trevor Siemian, who signed a one-year deal with the Jets in March, will start in his place Monday night.

“Anytime you lose your quarterback, it’s a big deal,” said Dowell Loggains, the team’s offensive coordinator and quarterbacks coach. “It is a next man up mentality. Trevor has been here the whole offseason. We’re excited about him.”

Siemian, 27, has not played in an NFL regular season game since Dec. 14, 2017. He is 13-11 with 30 touchdowns and 24 interceptions in his 24 career starts, all with the Denver Broncos.

“I’ve been there and done it a little bit,” Siemian said. “It’s been a while. So, like I said, I’m chomping at the bit to compete and get out there with the guys. I feel comfortable.”

Monday’s matchup is the start of a tough stretch in the schedule for the Jets. After Cleveland, the Jets will travel to Foxborough, Massachusetts, to face the New England Patriots in Week 3, followed by a bye week. They will then play at the Philadelphia Eagles before returning for home games against the Dallas Cowboys and Patriots.