Steelers center Maurkice Pouncey was getting treatment for his sprained left ankle while his teammates practiced Thursday for the Super Bowl.
Pouncey's availability is in question because of the injury sustained in the AFC championship. Coach Mike Tomlin told a pool reporter after practice "it's getting to be witching hour for Maurkice."
If he can't play Sunday, Doug Legursky would make his first NFL start at center.
Defensive end Aaron Smith, who has been out since Oct. 24 with a torn triceps muscle, didn't participate in scrimmages.
The Steelers worked out at TCU's indoor practice field. Horned Frogs coach Gary Patterson, several assistants and a few players watched.
Green Bay receiver Donald Driver missed practice Thursday because of an injured thigh and probably will miss another.
Packers coach Mike McCarthy told a pool reporter that Driver wanted to practice Thursday, but "I'm not taking any chances with him."
Driver missed a full game and parts of two others this season because of the same injury.
Linebacker Erik Walden also missed practice because of a sprained ankle. He was hurt in the NFC championship game, and he tested it in practice Wednesday. McCarthy said Walden is likely to sit out more practices.
"He was very sore, which is why we limited him today," McCarthy said. "It's up the air with him right now. We'll see how he feels tomorrow. Even if he feels a lot better, he'll be limited. I'm going to hold him back and give him every chance to be ready for the game."
The workout again was at the indoor facility at Highland Park High School. It lasted 1 hour, 45 minutes and was not in pads.
But there was still some tussling. Offensive lineman Evan-Dietrich-Smith, working with the scout team, and linebacker Rob Francois got into a pushing and grabbing match. Teammates stepped in and separated them, and there were no further incidents.
"Frankly, we feel like we're ready to go," McCarthy said. "We've got everything in, so tomorrow will be completely review for us."
The Associated Press contributed to this report.