Coach Kyle Shanahan said Ford and safety Jaquiski Tartt are "day-to-day." Tartt sustained a toe injury in the 49ers' 41-17 victory over the Cincinnati Bengals. Ford did not play any in the second half of that game.
Ford did not play during the preseason due to knee tendinitis and quad irritation. He aggravated his condition on Sunday but felt as if his condition improved on Wednesday.
"For him to have a setback like he did after missing some camp, there's always some concern but he is day to day," Shanahan said.
"We'll play it safe the next two days, which makes me somewhat optimistic for the game."
Four other players will not be available Sunday against the Steelers due to injuries: Running back Tevin Coleman (ankle), wide receivers Jalen Hurd (back) and Trent Taylor (foot), and offensive tackle Joe Staley.
Defensive back Jimmie Ward will be limited in practice Wednesday as he works back after undergoing surgery two weeks ago to repair a broken finger.
49ers' Dee Ford, Jaquiski Tartt listed as day-to-day with injuries originally appeared on NBC Sports Bay Area