Pittsburgh center Maurkice Pouncey sat out practice Wednesday but still expects to play in the Super Bowl.

The Steelers aren't as optimistic about defensive end Aaron Smith. He dressed for the nearly two-hour practice but was still limited by a torn triceps, which has kept him out since he was injured in late October.

Asked if he still thought the 34-year-old Smith could play Sunday, coach Mike Tomlin said in the pool report, "I do, but it's fading." Second-year player Ziggy Hood continued to fill in at left end.

Pouncey sustained a high left ankle sprain in the AFC championship game. The rookie hopes to practice Friday and reiterated his chances of playing against the Green Bay Packers are 75 percent. He's been walking with a protective boot.

"He's a center who's got a high ankle sprain," Tomlin said. "If he played a skill position, we wouldn't be having this conversation. But he's an interior lineman. Whether he practices depends how he responds to treatment."

Meanwhile, Green Bay outside linebacker Frank Zombo, who missed the last six games with an injured right knee, fully participated in practice. Another linebacker, Erik Walden, was limited after hurting his ankle in the NFC title game. He worked primarily with the second team.

"How Erik responds to this practice will be big," coach Mike McCarthy said in Green Bay's pool report. "He practiced and took reps in every team drill. That was the high end of what we were going to try to give him today. It'll be great if he feels good tomorrow."

Zombo appears to be back at full speed.

"Frank looks good," McCarthy said. "I wanted to get him as much padded work as possible. It seems like December 12th is the last time he's been in pads. We even got him a bunch of reps on special teams, too."

Also limited for the Packers: tackle Chad Clifton (knees) and offensive lineman Jason Spitz (calf).

With Pouncey on the sideline, Doug Legursky faces the daunting possibility of making his first career start at center in the Super Bowl.

Pittsburgh centers have traditionally been athletic pullers and blockers, and Legursky fit that description in the first practice of the week. The 6-foot-1, 315-pound Legursky was quick to get outside on some running plays, the way Tomlin has asked.

"He's an athletic guy," the coach said. "I've challenged him to get out and run and lead that group."

McCarthy sought to simulate a normal Wednesday practice by focusing on base packages, third-down situations and specific special teams scenarios.

The session was roughly 25 minutes shorter than a usual Wednesday practice because the team did its preliminary work at the hotel before busing to Southern Methodist University, where the players changed into their practice gear for the short ride to Highland Park High School's indoor facility.

The team will work out at Highland Park on Thursday and Friday, as well, using the indoor facility to stay out of the frigid temperatures in Dallas.

"The guys are fresh, they're ready," McCarthy said. "I want to keep the risk for injury low leading up to the game, which is why we shortened some things today. But it was good to get back in pads. The guys were flying around. They were banging pretty good."

Packers kicker Mason Crosby and punter Tim Masthay worked out beforehand at Cowboys Stadium and could do so again this week.