Mack was limited in practice Friday for the third straight day due to a knee injury and is listed as questionable on the injury report. But the three-time first-team All-Pro told reporters during a video call that he intends to play, saying: "I know I'm going to be ready on Sunday."
Mack played 67 of 78 plays (86 percent) in last Sunday's season-opening win over the Lions, registering four tackles.
Quinn is also listed as questionable with an ankle injury. But he practiced without restrictions Friday after being limited Wednesday and Thursday. The veteran free-agent acquisition was held out of the season opener due to the injury after being unable to practice during the week leading up to the game.
"We were really excited to be able to sign Robert Quinn," said coach Matt Nagy. "I think he's put together a good week, and we'll just keep an eye on where he's at and how we want to do things with him. But anytime you have Robert Quinn on one side and Khalil Mack on another side, offensively, you've got to know where everybody's at now. You can't just pick a side. It's exciting. We'll see exactly where we'll go with it, but I thought Robert had a good week."
Asked what he needs to see Sunday morning to indicate he'll be ready to play, Quinn said: "Well, the sun will be the first thing. That'll let me know I'm alive. No. 2, I guess, to see my jersey over the pads and see if they'll let me play. And after that, we'll just take it how the cards are dealt."
Quinn is eager to join Mack and the rest of the Bears defense on the field.
"It's not just Khalil; I've been anxious to get out there and get to play with the whole defense," Quinn said. "But now, looking at the grand scheme, it's really just to be able to join the team and get to really feel that locker room energy. I was kind of on the back end while rehabbing, but I'm definitely excited to see what I can bring, see what we can bring as a tandem, and not just us. We've got a great group of [outside linebackers], so whoever is out there, I think we're all capable of making plays."
In other injury news, defensive tackle Akiem Hicks practiced without restrictions Friday after sitting out Thursday with an illness.
For the Giants, safety Adrian Colbert (quad) has been ruled out of Sunday's game after missing practice Friday, while receiver Golden Tate (hamstring) and linebacker Carter Coughlin (hamstring) are questionable after being limited.
Roster moves: The Bears on Friday signed linebacker Devante Bond and rookie offensive lineman Dieter Eiselen to their practice squad.
Bond originally joined the team last Dec. 9 and played in the final three games of the season. He was waived July 26.
Bond was selected by the Buccaneers in the sixth round of the 2016 draft out of Oklahoma. After spending his rookie season on injured reserve, he appeared in 29 games with six starts over three seasons with Tampa Bay, registering 26 tackles and one tackle-for-loss.
Last year Bond played in four games with the Buccaneers, recording three tackles, before being released on Oct. 15. In 2017, he led Tampa Bay with 10 special-teams tackles.
Eiselen signed with the Bears in May as an undrafted free agent from Yale and was waived as part of final cuts Sept. 5.
Growing up in South Africa, Eiselen was an acclaimed rugby player and Olympic weightlifter. Intrigued by American football from watching it on TV, he traveled 8,000 miles to attend a football camp in Virginia as a high school senior.
Eiselen ultimately decided to play the sport for one year at Choate Rosemary Hall, a private college preparatory boarding school in Connecticut, before transferring to Yale.