Langford wore a walking boot in the AT&T Stadium visitors’ locker room after the game, but the injury is not believed to be long term.
Rookie fifth-round pick Jordan Howard replaced Langford and rushed for 45 yards on nine carries, plus he caught four balls for 47 yards.
Howard is the logical choice to assume a larger role if Langford misses time, but Fox was not ready to fully commit to the youngster.
“Remember, Jordan is a rookie that we’ve seen for three real NFL football games,” Fox said. “So we’ll kind of evaluate as we move forward. I think it would be kind of not right for me to answer that at this point.”