GREEN BAY — The Green Bay Packers' offensive line is in flux yet again.

Center Scott Wells returned to practice Monday, but promptly was back on the sideline Tuesday after suffering what coach Mike McCarthy termed "a setback" with his lower back injury.

Wells, who missed virtually all of training camp with the injury and played in just one preseason game (at San Francisco on Aug. 16), was thought to have returned to form after taking more than two weeks off and focusing on rehabilitation.

"I think it was 16 days that he has been going through the rehab, and this is unfortunate," McCarthy said. "I know Scott is frustrated."

As a result, the Packers' offensive line for Monday night's regular-season opener against the Minnesota Vikings likely will look like it did in the preseason finale against Tennessee and it did in practice Tuesday: Chad Clifton at left tackle, Daryn Colledge at left guard, Jason Spitz at center, Tony Moll at right guard and Mark Tauscher at right tackle.

The timing couldn't be worse, either, since the Packers will face what McCarthy called "the best defensive tackle tandem that we will play" in Minnesota's Pat Williams and Kevin Williams.

"It's a concern with the whole offensive scheme and what you are trying to do, but we've trained for this particular situation," said McCarthy, who had Colledge also taking snaps at center in case of emergency. "I didn't think we would be experiencing it in Week 1, but that's part of the game. I'm not really concerned about it. I'm just planning and working through it."

Health watch

While McCarthy admitted that halfback Ryan Grant not practicing Tuesday because of soreness in his hamstring was "a legitimate concern," Grant didn't have the kind of setback Wells experienced and vowed to be ready to play against the Vikings.

"They're just being cautious with me because it's a long week," Grant said. "I'm fine."

Linebacker A.J. Hawk (chest), wide receiver James Jones (right knee), guard Josh Sitton (left knee), safety Charlie Peprah (hamstring), linebacker Tracy White (ankle) and defensive ends Jeremy Thompson (groin) and Kabeer Gbaja-Biamila (knee) did not practice.

Asked if he had encouraging news on Hawk, who hasn't participated since straining a chest muscle in the preseason opener Aug. 11, McCarthy said, "He's way ahead of schedule, and that's the problem that you have when you have to make these types of decisions. The doctor has a criteria of what he thinks the time frame may be, and then you have the individual, who has no history of being injured, and (has) just attacked (rehabilitation). If you asked A.J., he'd say he could play yesterday."

Getting acquainted

Mason Crosby said he, new long snapper Brett Goode and new holder Derrick Frost had no problems while kicking together for the first time in practice Tuesday.

"It felt like we had been doing it awhile already," Crosby said. "There were really no instances where I was like, 'This a change at all,' because they really took care of business."

Goode also appeared to snap well to Frost during the punting portion of practice open to reporters, and Frost's 12 punts with the wind were all solid.