The New York Jets signed quarterback David Fales to back up Luke Falk for Sunday's game against the New England Patriots, the team announced.

The Jets (0-2) have been left to scramble at the quarterback position with starter Sam Darnold sidelined with mononucleosis. He missed Monday's 23-3 loss to the Cleveland Browns and will miss Sunday's game at New England as well. He said Tuesday during his weekly spot on ESPN New York's The Michael Kay Show that he is feeling better and his goal is to return for the Jets' Week 5 game against the Philadelphia Eagles. The Jets have a bye in Week 4.

Trevor Siemian started Monday night's game but was lost for the season when he suffered torn ligaments in his left ankle on a late hit by the Browns' Myles Garrett. Falk, who had been elevated from the practice squad before that game, went 20-for-25 passing for 198 yards in relief and will start against the Patriots.

Siemian was placed on injured reserve Wednesday, which opened the spot on the active roster for Fales.

Fales, as well as Falk, played for Jets coach Adam Gase in Miami and are familiar with his offense. Fales last played in a regular-season game in 2017 with the Dolphins; he is 31-for-48 passing for 287 yards with one touchdown and one interception in three games in his career.

ESPN's Rich Cimini contributed to this report.