Peyton Manning's left foot was sore Friday so he didn't practice after running the Denver Broncos' scout team for two days.
Manning's foot has bothered him for months and he's been sidelined since mid-November with a torn plantar fascia that required a cast or boot for 10 days.
He returned to practice Wednesday but after two days of running the scout team, he reported to work saying he was sore.
"So we said, 'OK, we'll stop for the weekend and go from there,'" coach Gary Kubiak said.
Kubiak had already ruled out the league's only five-time MVP for Sunday's game at Pittsburgh (8-5), when Brock Osweiler will make his fifth consecutive start for Denver (10-3).
The Broncos practiced outside on damp fields Friday after spending two days inside because of a heavy snowstorm and frigid temperatures, but Kubiak said "that had nothing to do with" holding Manning out.
Manning was walking around after practice without any limp and Kubiak said Manning would make the trip "and be a part of everything we're doing and he'll be on the sidelines, I'd assume. Sidelines or press box, one or the other, but I'd assume it would be sidelines."
This will be the first trip Manning has made since being sidelined. He missed trips to Chicago and San Diego and watched the Patriots-Broncos game from inside the locker room before watching Denver's 15-12 loss to Oakland last weekend from the sideline.
Manning's father, Archie, said in a television interview this week that his son's left foot was bothering him since before the season even started. On Dec. 2, Manning told a few news outlets, including The Associated Press, in an interview at his locker that he'd been ailing for some time but he declined to say exactly when his foot began bothering him.
"I know that his foot has been sore since we left Indianapolis" on Nov. 8, Kubiak said. "So, it's something that we've been dealing with and trying to deal with it the right way to get him back to where he feels really good. The progress has been very good. That's all I know."
In addition to Manning, Kubiak said safeties T.J. Ward (ankle) and Omar Bolden (hamstring) and linebacker Lerentee McCray (hamstring) would miss Sunday's game.
Also, safety Darian Stewart (hamstring) was 50-50 after missing practice all week. He's one of a half-dozen players listed as questionable.
For the second straight week, the Broncos had 22 players listed on their injury report.
"Half the damn team," Kubiak said.
He said he expects Ward to return to practice Wednesday.
But Bolden had a setback in his return.
"We thought he would be ready to go," Kubiak said. "He practiced on Wednesday. He came out on Thursday, went about five minutes and said it was bothering him, so we shut him down."
Notes: DL Malik Jackson returned to practice Friday as a proud first-time papa following the birth of his daughter, Nahla, on Thursday. "My whole goal is just make her a trust-fund baby. I have the right job to be able to do that," said Jackson, a pending free agent who is in line for a big pay raise this offseason.