New York Jets quarterback Sam Darnold will miss Monday's game against the Cleveland Browns after being diagnosed with mono, head coach Adam Gase announced Thursday.
Gase said Darnold could miss multiple weeks, and Trevor Siemian will start in his absence, according to ESPN's Rich Cimini.
Darnold was sent home from Wednesday's practice with what was initially believed to be strep throat. However, the young passer's condition apparently deteriorated quickly:
To protect his teammates, Darnold will be quarantined in his apartment until he's cleared by New York's medical staff, according to ESPN's Chris Mortensen.
The Jets' offense was dealt another blow Thursday, as Gase also revealed that star running back Le'Veon Bell is dealing with a sore shoulder. He will undergo an MRI and sit out Thursday's practice.
Darnold was solid in New York's season-opening loss to the Buffalo Bills, throwing for 175 yards and one touchdown.
Siemian didn't appear in the regular season last year while playing for the Minnesota Vikings but started 24 games for the Denver Broncos from 2016 to 2017.
With Darnold out, the Jets plan to promote second-year quarterback Luke Falk from the practice squad to serve as Siemian's backup, according to Manish Mehta of the New York Daily News.