GREEN BAY – The Packers are still working through the possibilities at their two most stressed positions on the roster – running back and cornerback – as they begin preparations for Thursday night’s visit from the Bears.

Eddie Lacy gritted through 17 carries for 65 yards on a bum ankle but was still being evaluated as Head Coach Mike McCarthy spoke to the media early Monday afternoon. Backup James Starks had knee surgery on Sunday and is out for now with a timetable to be determined.

Ty Montgomery served as the No. 2 back in the 30-16 loss to the Cowboys and is in line for a bigger role on offense in general after catching 10 passes for 98 yards.

But McCarthy wouldn’t say whether or not another true running back, such as practice-squad rookie Don Jackson, would be added by Thursday.

“You definitely want to, but it depends on how you want to play the game,” McCarthy said of fortifying the running back spot. “It’s a long year. You start making roster moves … it’s just never really one factor.”

The Packers lost No. 3 quarterback Joe Callahan to a waiver claim last week to clear roster space, and releasing any other young players would carry the same risk.

The team is sifting through all those implications as it also deals with a cornerback position that is banged up. Green Bay’s top three of Sam Shields (concussion), Damarious Randall (groin) and Quinten Rollins (groin) are all battling injuries.

“We have two positions that need attention and these injuries we have are not of long-term nature,” McCarthy said. “You just have to work through it. I don’t know if we’ll have it sorted out until Tuesday maybe Wednesday.

“It’s never just give me a running back or give me another corner. That is the chess match right there. It’s managing the roster.”

On offense, right tackle Bryan Bulaga (back) has a good chance to play, according to McCarthy, but he wasn’t sure of his status. Rookie Jason Spriggs filled in late in Sunday’s game.

Montgomery’s outing was a bright spot, though a lost fumble in the fourth quarter took some shine off it. As he puts together a game plan for the Bears, McCarthy is looking at who needs to be more involved.

“Frankly, we need to get Ty the ball,” McCarthy said. “It’s about creating opportunities to get certain players the football. I did not get the ball to Randall Cobb enough.”

Cobb had seven catches for 53 yards and a late touchdown, his first of the season, but quarterback Aaron Rodgers was unable to connect with him on a couple of other big chances in scoring territory.

Missed opportunities combined with four turnovers – Rodgers had a fumble and interception, and Jordy Nelson also lost a fumble – leave the Packers a lot to clean up in a short time. McCarthy’s initial focus is on ball security, because against Dallas the offense turned the ball over in the red zone for a second straight game, a miscue that “takes a shot out of your energy on the sideline.”

Protecting the football has been a McCarthy hallmark. The Packers have to get back to it and reverse the current trend.

“You look at those giveaways yesterday, every single one of them was avoidable,” McCarthy said. “I have great confidence we’ll perform at the level we have the last 10½ years. This is not the way we play football. We will do a better job.”

Finding the best offensive packages and the right combinations of players is the next, or concurrent, step to regain the efficiency the Packers need.

“We’re going through a patch right now adjusting more than you like, but that’s part of the challenge for the 2016 Packers,” McCarthy said. “We’re going to get better. That’s all I know.”