Dart was knocked down on a third‑and‑eight play when Rams linebacker Byron Young struck him from the right, sending the quarterback into linebacker Josaiah Stewart, who undercut his legs and caused a heavy fall.
Giants coach John Harbaugh said the injury, initially diagnosed as a sprained medial collateral ligament, is still being evaluated and an MRI will determine whether more serious damage exists.
Harbaugh declined to confirm reports that the injury is worse than first thought, describing the situation as “in the neighbourhood” and emphasizing that the team must “prepare for the range of possibilities.”
He added that the Giants will announce a timeline once the medical evaluation is complete, but expressed confidence that backup quarterback Jameis Winston can step in for as long as needed.
The loss also saw other Giants injuries: pass rusher Brian Burns sprained his left ankle, left tackle Andrew Thomas suffered a lower‑body issue in the fourth quarter, and wide receiver Malik Nabers dislocated his right shoulder early in the game.
The Giants, now 1‑1 on the season, travel to face the Tennessee Titans next week, and Harbaugh urged his squad not to be discouraged, reminding them that injuries are a routine part of NFL football.