Davis re-aggravated the injury in the ninth-ranked Gamecocks' 52-28 loss to No. 21 Texas A&M last Thursday. Davis had missed time during fall camp with rib problems.
Spurrier said Davis was in pain and his condition would be re-evaluated later this week. The Gamecocks (0-1) face the Pirates (1-0) at Williams-Brice Stadium on Saturday night.
Davis ran for 1,183 yards last season, but managed just 15 yards on six carries against the Aggies.
Spurrier said backup Brandon Wilds was most likely to start if Davis can't go. The coach said reserves Shon Carson and David Williams would also see action.