Yes, the announcers commented that Ace sprained his ankle on the play where he fumbled, and he would probably not return in the second half.
Our RBs have been snakebit this year:
Hollings - ACL; out for year
Ford - Concussion; out indefinitely
Hatch - Still not back from 2000 ACL injury
Ezimife - Sprained ankle; hopefully not serious
Clinkscale - Pulled hamstring; hopefully not serious
If I'm PJ Daniels, I'm watching where I step carefully over the next week.