Foles threw his 10th interception of the season before getting hurt Sunday. It was returned 51 yards for a touchdown by Houston's A.J. Bouye. Foles had two interceptions last year and 27 touchdowns.
Sanchez, who led the New York Jets to the AFC championship game in his first two seasons in the NFL, quickly scored after entering the game. He set the touchdown up with a 52-yard pass to Jeremy Maclin, then scored with an 11-yard pass to Jordan Matthews.
Sanchez had a strong preseason with the Eagles. He missed the 2013 season after tearing the labrum in his right shoulder in a preseason game. He lost his starting job to Geno Smith and was released by the Jets in March.