Williams will miss anywhere from two to six weeks with a fractured shoulder, leaving the Vikings (9-5) without their best run stopper as they prepare to face the two best rushing teams in the league with a playoff berth hanging in the balance.
"He's a different kind of cat and a tough one at that," coach Brad Childress said when asked about the possibility of Williams being ready should the Vikings qualify for the playoffs. "We'll see. He's fully informed. He's looked at all the pictures and had an idea of where it's at. It's just a matter of getting that thing settled down and let it start to heal."
Williams was hurt Sunday in a 35-14 rout of the Arizona Cardinals. It's a big blow to a Vikings defense that is second in the NFL against the run. They need only one more victory or a Bears loss in the final two weeks to capture their first NFC North title.
The Vikings have won four in a row to remain in the running for the NFC's second seed, which would bring with it a first-round bye.
"Coach wants us to go one game at a time, but of course we do think ahead a little bit," tight end Visanthe Shiancoe said. "But that is motivation. The thing is it's right there for the taking.
"These are teams that I feel we can really beat," he added. "I'm going to say something kind of outlandish, but if we play our A-game, I don't see any team in the NFL beating us, to be honest."
The A-game, of course, always has included Big Pat in the middle.
Williams is the emotional leader and chief run stopper on the line. With the Atlanta Falcons (No. 2) and the New York Giants (No. 1) visiting the Metrodome in the final two weeks of the regular season, the timing couldn't be worse.
Backup Fred Evans will get most of the snaps in Williams' place, though Childress said the team will look at every option to fill the 320-pound hole in the middle of the defense.
"We'll look and see how we want to rotate those guys through there from Kevin Williams kicking over to nose from time to time to Letroy Guion and Jimmy Kennedy will factor in," Childress said. "So it's a good thing to have a little depth in there."
Pat and Kevin Williams have been playing because a federal judge in Minnesota issued an injunction blocking their league suspension for violating the substance abuse policy. The Williamses are among five players challenging the suspensions because they say the product they were using, StarCaps, did not list a banned diuretic on its ingredients.
The diuretic, bumetanide, can be used as a masking agent for steroids. Diuretics also aid in weight loss.
Lawyers for the players' union say the case is likely to drag on well past the Super Bowl, news that came as a huge relief to a team that is starting to play its best football of the season with the playoffs approaching.
The Vikings have won six of their last seven games to overcome a 1-3 start to the season that had fans calling for Childress's dismissal. Yet the players and coaches stuck together and now find themselves on the verge of their first playoff appearance since 2004.
"It's a good dynamic," Childress said. "They all push each other and they understand they all have roles and some of their roles change week to week; but they all want to improve and get better."
Evans' role has been in flux more than most. Two weeks ago, he was being asked about stepping in for Pat Williams after the league announced the four-game suspension.
Two practice days later, Evans returned to his backup role when a judge issued a temporary restraining order that allowed the Williams Wall to play.
Now here he is again, back in the spotlight.
"If there is anything I know about Pat, he'll be ready," Evans said when asked if he thought Pat Williams would be back for the playoffs. "And until that time, until he's ready, I'm going to hold it down the same way he did."