Pouncey was listed as questionable on the Steelers' injury report, but told ESPN's Josina Anderson Friday he would miss the game.
"I am very distraught about not being able to play in this game," Pouncey said. "Since I am unable to be on the front line grinding with my teammates I wil be on the sidelines pushing them and hyping up the Steeler Nation. Go Steelers."
Pouncey missed practice Thursday and Friday because of increased soreness in his left ankle. The Pro Bowl center played in the regular-season finale against Cleveland last week after missing two games but complained of problems with the ankle following Wednesday's practice.
Doug Legursky likely will start in Pouncey's place, as he did in last year's Super Bowl, when Pouncey was sidelined with an injury to the same ankle.
Legursky, who missed last week's game at Cleveland with a left shoulder injury, practiced at center this week and started at center against San Francisco and St. Louis when Pouncey couldn't play.
Legursky has started three games this year at right guard, five at left guard and two at center.
"It's no different for me," he said. "I practice each week as if I'll play multiple positions anyway, so it's not a problem."
For the Broncos, safety Brian Dawkins, who has been hampered by a neck injury and hasn't practiced in weeks, was ruled out.
Roethlisberger practiced Friday and was listed as probable despite a high ankle sprain that's bothered him for the last month. He originally hurt the ankle Dec. 8 in a win over Cleveland then missed a start against St. Louis on Christmas Eve. He started against the Browns last Sunday and acknowledged the ankle suffered a "setback" sometime in the second half.
The two-time Super Bowl winner was limited in practice Wednesday but was full-go Thursday and Friday.
Linebackers James Harrison (toe) and LaMarr Woodley (strained left hamstring), defensive end Brett Keisel (groin), safety Troy Polamalu (calf) and tackle Jonathan Scott (back) also were listed as probable and were expected to play.
Cornerback Cortez Allen (left shoulder) and running back Mewelde Moore (right knee) are out for the Broncos game. Regular starting running back Rashard Mendenhall was lost for the playoffs last week with a torn right ACL.
"It's just a part of football," Legursky said. "Every year, it's something. As long as you stay focused on what you need to do to get the job done, that won't be a problem."
Information from The Associated Press was used in this report.