CHARLOTTE – The Panthers seemed confident during the bye week that running back Christian McCaffrey was on the right track in his recovery from a shoulder injury.

Now, there's a new issue to deal with, one of many challenges the Panthers faced when they hit the practice field Wednesday.

McCaffrey was listed as limited in practice with a quad injury in addition to the previous shoulder problem.

"At this point, I don't know, we have to monitor it day-to-day," Panthers coach Matt Rhule said of McCaffrey's status for Sunday's game against Denver. "I think he might have tweaked it last week, felt good going into today, and got out there and it got tight on him. So we limited him.

"From what I know right now, we'll handle it day-by-day and see if he's able to play with the quad."

The number of missing guys on the other side of the ball was also jarring and left the Panthers with some interesting looks.

With six players on the active roster still on the reserve/COVID-19 list, the Panthers were forced into some unusual combinations of players for practice.

Defensive linemen Derrick Brown, Zach Kerr, and Yetur Gross-Matos remain on the COVID-19 list, along with linebacker Shaq Thompson and wide receivers DJ Moore and Curtis Samuel. Tackle Greg Little was activated from the list Wednesday, so he was at practice.

But the lack of defensive linemen available was glaring. Ends Brian Burns and Austin Larkin and tackles Bravvion Roy and Efe Obada were the only members of the 53-man roster practicing since defensive end Marquis Haynes Sr. was out with an illness.

(The Panthers also have practice squad defensive tackle Bruce Hector on the COVID-19 list, leaving practice squaders Woodrow Hamilton, Mike Panasiuk, and Jonathan Wynn as the reserve linemen filling in for practice.)

"We've kept a lot of guys on the practice squad that we have confidence in that could be elevated, that know what we're doing," Rhule said. "I think the guys that are going to be available Sunday have to be ready to play 60 or 70 snaps. We'll go through the week and see who's available, and we'll ask those guys to empty their tanks and play hard and play for a long time. And if we elevate someone from the practice squad, we've done that before, I trust those guys and I know they'll play well."

There was also an adjustment in the secondary.

Cornerback Donte Jackson was back after missing the last two weeks plus the bye week, letting his toe injury heal. He was listed as limited, but said his toe felt good after taking some time to do some different types of rehab, including pool work. Veteran cornerback Rasul Douglas was not present Wednesday (non-injury).

Offensive lineman Dennis Daley (concussion) was wearing the red no-contact jersey, and didn't participate. He missed the Vikings game before the bye with a concussion. Linebacker Sam Franklin Jr. (ankle) was also limited.

The Panthers also designated linebacker Adarius Taylor to return from IR, opening the window for him to practice to see if he's ready to be activated. They also signed kicker Lirim Hajrullahu (Western Ontario, Can.) to the practice squad, but Rhule made it clear that Joey Slye remained the team's kicker.

You can see Wednesday's entire injury report here.