The Steelers said earlier in the day that they were waiting for a second medical opinion on the right foot Bell injured Monday night, and they ruled him out for the team's preseason game Saturday against the Kansas City Chiefs.
The Steelers sent Bell's MRI scans to Charlotte, N.C.-based foot specialist Dr. Robert Anderson for a final determination on whether the running back requires surgery. If surgery is needed, Bell could miss the entire season.
Coach Mike Tomlin declined to talk about Bell's injury after Wednesday's practice, telling reporters he still had to meet with team doctors. Tomlin went on to say he would address all injuries at his Thursday news conference at 12:30 p.m. ET.
Bell had an MRI taken Tuesday, and Tomlin said in a statement that the Steelers should have a final diagnosis "over the next couple of days."
Bell left the Steelers' 24-13 loss to Washington early after spraining his right foot.
The team's second-round pick in April, Bell had been hampered by a knee injury earlier in the preseason and missed the Steelers' first preseason game.
The 6-foot-1, 244-pounder was listed as the co-starter on the Steelers' depth chart with Isaac Redman, and he was expected to play a big role in the running game this season.
The Steelers have suffered a rash of injuries at running back. Redman (stinger) and LaRod Stephens-Howling (knee) did not play against the Redskins, and Baron Batch left the game with a stinger, leaving Jonathan Dwyer and Alvester Alexander as the only healthy running backs.
Tomlin said the Steelers held Stephens-Howling out of the game as a precaution, and he is expected to return to practice this week.
Bell, meanwhile, received some advice from veteran safety Ryan Clark following the rookie running back's abbreviated NFL debut Monday night.
Clark told Bell to make sure he was fully healthy before he returns to the playing field.
It was the same thing Clark told Bell during training camp after the latter went down the second time with a left knee injury.
"I told him, 'I understand that you want to prove to us that you're tough, that you want to prove to us that you're durable, that you're willing to go out and do whatever it takes to help us, but also understand that we're not going to win the Super Bowl this week. We weren't going to win it last week,'" said Clark, one of the team leaders. "He's proven to me that he wants to be out there, that he wants to try to fight through injury. Now he needs to get himself healthy."
What is key as Bell deals with another injury is making sure he stays engaged in meetings and at practice. Redman said he plans on peppering Bell with questions during practice to make sure the rookie doesn't lose focus.
"The mental reps are the biggest key when you're injured, to stay in practice, because a lot of guys, especially younger guys, when they get hurt, they tend to kind of drift away and become a guy that coaches always have to talk to and make sure you're paying attention at practice," said Redman, who hopes to play Saturday night. "As an older guy, you try to help them not get into that habit."
Bell had been one of the stars of training camp, and one thing Clark has stressed to the 48th overall pick is to keep his eye on the big picture.
"I've watched him run the ball in practice enough to know that he can be effective," Clark said. "I don't know what the situation is with this injury, but I want him to be fully healthy and be at full speed when he comes back because you don't want these things to continue to nag him not only this year but throughout his career. He has an opportunity to have a long football career. It's not all about today."
Information from ESPN's Ed Werder was used in this report.