Jets quarterback Trevor Siemian left Monday's 23-2 loss against the Browns with an apparent ankle injury.
Siemian grasped at his leg following a hit from Browns' defensive end Myles Garrett in the second quarter. The Jets quarterback was able to walk off the field at MetLife Stadium under his own power.
With Siemian and Darnold both unavailable, the Jets turned to Luke Falk, who threw for 198 yards in relieving Siemian.
New York promoted Falk to the team's active roster hours prior to its meeting with the Browns. The Jets claimed Falk off waivers in May after he spent the previous season with the Miami Dolphins and Tennessee Titans. Falk played in 42 games and threw 39 touchdowns across four years for the Washington State Cougars.
Siemian spent the first three years of his career with the Denver Broncos. He spent last season as the Vikings' backup quaterback before signing a one-year, $2 million contract with the Jets in March.