The 49ers could have a shortage at the slot.
First-string nickel cornerback Chris Davis (hamstring) did not practice Thursday, and a candidate to replace him, Keith Reaser, was also sidelined for a second straight day with an ankle injury.
Cornerback Jimmie Ward, who played in the slot in his first two seasons, could replace Davis if he is unable to play in the season opener Monday night against the Rams. If Ward moves back inside, rookie cornerback Rashard Robinson, a fourth-round pick, could take his spot outside.