New York Giants quarterback Jaxson Dart could miss the rest of the 2026 season after follow-up testing showed his left knee injury from Monday night’s loss to the Los Angeles Rams is more severe than first hoped, according to NFL Network’s Ian Rapoport and Mike Garafolo and parallel ESPN sourcing.

Dart, 23, was hurt on New York’s seventh snap when Rams linebacker Byron Young hit his right side and redirected him into Josaiah Stewart, who undercut his legs. He grabbed the left knee immediately, limped to the locker room, and was ruled out. After the 28-6 defeat, coach John Harbaugh said the injury looked “in the neighborhood” of a sprained MCL and that the Giants had avoided a “devastating outcome.” X-rays were negative; an MRI followed the team’s return east.

By Tuesday evening, multiple reports said Dart faces an extended absence with season-ending surgery possible. Harbaugh told reporters evaluations were ongoing, declined to confirm the bleaker timeline, and said the organization must “prepare for the range of possibilities.” He voiced confidence in Jameis Winston, who recently signed a two-year, $13 million extension, with Jake Haener on the practice squad as depth. Dart had opened the year with a sharp debut against Dallas—23-of-29 for 230 yards and three touchdowns plus 54 rushing yards—after a promising rookie season.

AP coverage stresses that no final medical decision has been announced by the club. Accounts agree the mechanism, the initial MCL neighborhood diagnosis, and Winston’s likely starting role; they diverge on surgery certainty until the Giants publish a definitive timetable for their young franchise quarterback.