New York JetsquarterbackBryce Petty, who is competing for the starting job, suffered a grade 1 MCL sprain but still hopes to play in the team's preseason finale, a source told ESPN NFL Insider Adam Schefter on Sunday.
Once he got to the sideline, Petty tried to jog, but he couldn't put any weight on the injured leg.
He had an MRI on Sunday. The Jets host the Philadelphia Eagles on Thursday in the team's final preseason game.
Petty replaced Christian Hackenberg to start the second half and threw three touchdown passes against the Giants' backups, compiling a perfect passer rating -- 158.3 -- as he completed 15 of 18 passes for 250 yards.
He is competing with Hackenberg and Josh McCown for the starting job.
Petty suffered two shoulder injuries last season, the second of which occurred in December and required surgery.
ESPN's Rich Cimini contributed to this report.