Young, backup to Eagles quarterback Michael Vick, pulled up with a limp after throwing an incompletion late in the first half. Young will have an MRI Friday to determine the severity of the injury.
Prior to his exit, Young went 15-of-23 for 193 yards. He hit Chad Hall with a 16-yard touchdown in the first quarter.
Third-string quarterback Mike Kafka threw for 76 yards in the second half. Dion Lewis and Graig Cooper both scored a 1-yard run for the Eagles.
Ellis Lankster provided one of New York's touchdowns by running an interception back 67 yards in the fourth period.
Philadelphia (3-1) begins the regular season at St. Louis. The Jets (2-2) open at home against Dallas.