Carlos Hyde has missed two straight practices due to a foot injury. Kirby Lee USA TODAY Sports

San Francisco 49ers running back Carlos Hyde did not practice for a second straight day Thursday due to a foot injury, putting his availability in question for Sunday's game at the St. Louis Rams.

Hyde has not practiced since San Francisco's home loss to Seattle on Oct. 22, a game in which he first said he was dealing with a stress fracture before clarifying his remarks to call the injury "something like that."

More from FoxSports

The 49ers have little in reserve behind Hyde. Backup Reggie Bush has missed three games due to a calf injury and his four carries for 21 yards against the Seahawks represented his highest workload of the season.

Hyde wasn't the only injury concern Thursday. Linebacker NaVorro Bowman, the team's leading tackler, wore a non-contact jersey and was limited due to a shoulder issue.

Also, leading receiver Anquan Boldin, who practiced fully on Wednesday, was limited in Thursday's practice because of an ailing hamstring. Boldin has six career 100-yard games against the Rams.