NFL.com's Ian Rapoport reported during Sunday's edition of NFL Network's "NFL Total Access" that Sanchez's MRI was inconclusive, and the Jets believe the injury is not a long-term issue.
Sanchez told one teammate "I'm fine," Rapoport said, but the Jets still are trying to figure out if the quarterback's injury is just a bruise -- it's at least that -- or if there is a separation.
Before the injury, Sanchez completed 5 of 6 passes for 72 yards in relief of rookie Geno Smith.
"We had the starting offense out there for three full quarters and I put Sanchez in, and unfortunately, the best play he makes probably all of preseason, he ends up getting hurt on it," coach Rex Ryan explained, via the Jets' official website.
Although there are no details on the severity of the injury to Sanchez's throwing arm, the early indications suggest Smith now is the heavy favorite to start in the Jets' season opener.
ESPNNewYork.com reported there is no guarantee Sanchez will be ready for Week 1. Despite the uncertainty of the current situation, however, Rapoport reported Sunday night that the Jets plan to ride things out and will not bring in other QBs for assessment.
Ryan is due to address the media at Monday's 2:15 p.m. ET news conference.