Aaron Rodgers has been dealing with a left knee injury. Rob Carr/Getty Images

It's already been a topsy-turvy season for the Green Bay Packers.

The season appeared to be in jeopardy in the opener against the Chicago Bears after superstar quarterback Aaron Rodgers was carted off the field in the second quarter with a left knee injury, but Rodgers battled back to lead an improbable late-game comeback. In the weeks that followed, the Packers settled for a tie with their toughest NFC North competition, the Minnesota Vikings, and on Sunday suffered a road loss to a Washington Redskins team that isn't expected to contend for a playoff berth.

When the Packers host the Buffalo Bills in Week 4 on Sunday, questions will linger not only over Rodgers' health but his effectiveness after being limited in practices.

All signs point to Rodgers starting, but the 34-year-old may not be in peak form. Despite not missing a play in Week 2 and Week 3, Rodgers has missed five practices, including Wednesday's session.

On Friday, head coach Mike McCarthy said Rodgers had looked good in Thursday's practice and "got everything accomplished that we set out to" and will participate in Saturday's walkthrough.

Rodgers has said that his knee is improving and feels good about his movement.

“I was moving a little better last week than the previous couple of weeks," Rodgers said. "So I’m just trying to do a little things in the pocket, extend plays when nobody’s open."

The Packers would almost certainly prefer to put the game out of reach in the first half to avoid Rodgers exerting too much energy against a struggling Bills squad that was trounced by the Baltimore Ravens in Week 1, 47-3. The Bills at the 11:22 mark of the third quarter trailed 40-0. In Week 2, the Bills suffered a home loss to the Los Angeles Chargers, 31-20, and trailed at halftime, 28-6.

However, McCarthy may not know what Buffalo team to expect on Sunday. The Bills shocked the Vikings in Minneapolis in Week 3, 27-6 — perhaps a sign they have ironed out some early season problems. The Packers are still listed as 10.5-point favorites.

Rodgers was sacked four times in each of the last two games and keeping him fit is the Packers' top priority. The offensive line won't be at full strength Sunday, as right guard Justin McCray is listed as "doubtful" with a shoulder injury. McCray missed practice on Wednesday and Thursday.

Veteran right tackle Bryan Bulaga is available despite dealing with a back injury.

“I feel good about it,” Bulaga said of his back. “I don’t think we’ll have any setbacks with it from now until then. Just try to decrease the swelling, the pain in it and calm that whole area down as much as you can.”

The Bills' defense, meanwhile, will be at full strength. Buffalo listed running backs LeSean McCoy (rib) and Marcus Murphy (rib), as well as tight ends Charles Clay (shoulder/hip) and Jason Croom (knee), as "questionable."

Should the Packers need to go to a backup quarterback, former Cleveland Browns starter DeShone Kizer is the No. 2 and rookie Tim Boyle is the No. 3.