Falk was thrown into a difficult situation because of Darnold's illness and Trevor Siemian's season-ending ankle injury.
In 16- and 25-point losses to the New England Patriots and Philadelphia Eagles, respectively, Falk passed for only 218 yards and threw three interceptions with no touchdowns. His Total QBR was 4.8, easily the worst in the NFL in Weeks 3-5. (The Jets had a Week 4 bye.)
In last week's loss, Falk was sacked nine times and committed four turnovers, two of which were returned for touchdowns. Coach Adam Gase, apparently frustrated by Falk's play, opted for Fales as the primary backup even though he hasn't thrown a regular-season pass since 2017. Fales received a mop-up series last week and has been active for two games.
The Jets have Mike White, a former Cowboys draft pick, on the practice squad. Falk could return to the practice squad, where he began the season.
Gase didn't dismiss the possibility of signing an experienced backup. Free agent Brock Osweiler, who played for Gase in Miami, would seem to be a logical option.
This is a tough break for Falk, who tried unsuccessfully to rally a winless team with major struggles on offense.
"Listen, man, Luke was thrown into a position that was very hard, very tough, something that many people cannot do," safety Jamal Adams said. "He did his best. That's all you can ask for."