Foster took a handoff late in the third quarter and appeared to injure himself before being contacted by a defender. He limped off the field and slammed his helmet in frustration before walking to the locker room.
Foster previously missed the Texans' game against the New York Giants in Week 3 due to a hamstring injury. He played in just eight games last season due to a back injury, for which he underwent surgery in November.
The 28-year-old had 15 carries for 56 yards against Philadelphia before exiting. He entered Sunday's game with 766 rushing yards and seven touchdowns this season on 146 carries.
The Texans trailed the Eagles 24-14 at the time of Foster's injury and went on to lose 31-21. Houston is now 4-5 and Philadelphia is 6-2.
- Ben Estes