The Packers have prepared all week as though they won’t have cornerback Tramon Williams in the lineup, but he still has a chance to play on Sunday, according to Head Coach Mike McCarthy.

Williams is officially listed as questionable on the team’s injury report with a shoulder injury, sustained in the fourth quarter of last Thursday’s season-opener. He didn’t practice all week, and even though McCarthy was hoping his starting corner would be able to do at least some on-field work, he’s confident Williams will be prepared to play if the shoulder is healed.

“Mentally, I do not worry about Tramon,” McCarthy said. “Tramon is a front-row, pen-in-your-hand, great-notebook (player). The mental preparation has always been excellent.

“This is purely a medical decision. If he’s physically ready, he’ll play. He’s doing everything he can. He’s doing round-the-clock treatment. He’s trying everything possible to get ready to go. It won’t be for lack of effort or want-to, that’s for sure.”

If Williams can’t play, the cornerback pecking order will adjust accordingly, with nickel back Sam Shields entering the starting lineup. Shields has been a de facto starter anyway because Defensive Coordinator Dom Capers plays so much nickel.

Depending on what the game plan is with Charles Woodson, Williams’ potential absence could mean Shields will get a hefty dose of Carolina’s Steve Smith, the Panthers’ No. 1 receiver.

“That’s what we preach all the time – if anybody goes down, somebody steps up,” Shields said. “If he can’t play, it’s my responsibility to step up.”

When Williams left last week’s game, Jarrett Bush moved into the nickel corner slot and Pat Lee was the dime corner when Capers used six defensive backs.

Against the Saints, on the play immediately after Williams departed, Bush was challenged by quarterback Drew Brees with a deep ball to Devery Henderson, but Bush broke up the pass nicely in the end zone. Earlier in the fourth quarter, Bush was called on to blitz and shared a sack with linebacker A.J. Hawk.

“It was definitely good to get in there and get involved in the game,” said Bush, who also made a big play in the Super Bowl as an injury fill-in, intercepting a pass. “It gets you into the game, what the offense is trying to do, what defense Dom likes to call. You get a feel for the game, and I have to keep it going and hit the ground running.”

Still, the Packers defense won’t be the same without Williams, who has 15 interceptions over the past three years and added three more in the playoffs last season. Over the course of the last five years, Williams has gone from practice-squad player to Pro-Bowler, and he’s one of three proven playmakers in the secondary along with Woodson and safety Nick Collins.

“I’ve always thought it was one of the strengths of our team,” Capers said. “We’ll have to wait and see what his availability is, but he’s made a lot of progress.”

His teammates certainly aren’t counting him out.

“I know he’s preparing like he’s getting ready to play,” Collins said. “We want Tramon back. We want him healthy. We don’t want him to come out there if he can’t do what he’s known to do.”

In other injury news, rookie linebacker Vic So’oto has been ruled out for the second straight week with a bad back. Defensive end Mike Neal (knee) and linebacker Frank Zombo (shoulder) were ruled out earlier in the week.

Rookie running back Alex Green was added to the injury report on Friday with an Achilles’ injury and he’s listed as questionable.

The rest of the Packers on the injury report are probable. That list includes tackle Chad Clifton (knee), tight end Jermichael Finley (ankle), cornerback Davon House (ankle) and tight end Ryan Taylor (hip). House and Taylor, both rookies, were inactive last week and would make their NFL debuts if active on Sunday.

Additional coverage - Sept. 16