By Simon Evans

DALLAS (Reuters) - Pittsburgh Steelers center Maurkice Pouncey missed practice for a second straight day on Thursday with a sprained left ankle and coach Mike Tomlin said his availability for the Super Bowl is in question.

"It's getting to be the witching hour for Maurkice," Tomlin told reporters after practice. "He's going to have to show us something very soon."

Pouncey's injury has been categorized as a high ankle sprain and he arrived in Dallas on Monday on crutches and has not trained.

The talented rookie will be replaced by the versatile Doug Legurksy if he is unable to play in Sunday's Super Bowl at Cowboys Stadium in Dallas.

Prior to practice, Pouncey said there was a good chance he would take part in Friday's session but acknowledged that if he did not his starting place was lost.

"If I am out there, I will play and if I'm not, I won't play. It's still a 75 percent chance. I am not doing any running yet," said Pouncey.

"We aren't going to push it that far yet. The biggest issue is the swelling. It's not all out yet and I'm trying to get all the rotation back into my ankle. It's been going good."

(Editing by Frank Pingue)