Gase added that Trevor Siemian will get the start under center, with Luke Falk serving as the backup:
This isn't the first injury- or illness-related setback for the 22-year-old Darnold, as he missed time with a foot injury that left him in a walking boot during his rookie season.
The Jets blew a 16-point lead in a season-opening loss to the Buffalo Bills last week, though Darnold had a decent game, completing 68.3 percent of his passes for 175 yards and one touchdown.
In Siemian, the Jets have a solid backup with starting experience. The Northwestern product played 11 games in 2017 and 14 games in 2016 for the Denver Broncos and entered the 2019 campaign with 30 touchdown throws and 24 picks.
He is 13-11 as a starter.