Jaxson Dart could miss the rest of the season after an MRI found his knee injury from Monday's 28-6 loss to the Rams was worse than first believed.
Jameis Winston is now the likely Week 3 starter against Tennessee on a short week, but his 11-of-27, 111-yard, one-interception relief outing underscored New York's thin depth.
Jimmy Garoppolo stands out among free agents because the 34-year-old still wants to play and has experience in west-coast concepts similar to the Giants' offense.
Trade options could include Eagles backups Andy Dalton or Tanner McKee, while Tua Tagovailoa may be a cheaper fallback if Atlanta eventually makes him available.
With only Dart and Winston on the active roster through two games, the Giants are weighing outside help to keep their season from unraveling.