Though the Vikings plan to start Jaren Hall at quarterback on Sunday in Atlanta, they'll have Joshua Dobbs available as his backup.

Coach Kevin O'Connell said Friday that Dobbs would be active for Sunday's game against the Falcons as the team's No. 2 quarterback behind Hall as the rookie makes his first NFL start with Kirk Cousins on injured reserve. Dobbs, who was acquired in a trade with Arizona on Tuesday, absorbed enough of the playbook this week for the Vikings to plan on him as the backup ahead of Sean Mannion, who remains on the practice squad.

"He's very intelligent, a great communicator and I thought he had a good week of practice," O'Connell said of Dobbs. "We're going to get some extra work in with him [between Friday and Sunday]. But he's going to go into the game active as the backup."

If Hall were injured or ineffective enough to merit a quarterback switch, O'Connell said he felt like Dobbs could run enough of the offense that the Vikings wouldn't have to condense their game plan. However, he said, "I don't know if that's necessarily required.

"I would much rather him be able to pick and choose. We've got plenty of plays, plenty of inventory. To me, it's about his comfort level, with a similar process to what we'll do with Jaren, making sure he's got a role in kind of talking through certain aspects of the game plan; where he likes certain things over the other. The reason why we put some volume in is so we can pick and choose as we get through the later part of the week."

Jefferson, Mullens return to practice still TBD

The Vikings could open the window for Justin Jefferson and Nick Mullens to return to practice from injured reserve as soon as next week, potentially clearing the way for the receiver and quarterback to play as early as Nov. 12 against the Saints at U.S. Bank Stadium. O'Connell said Friday, though, he did not yet have the information about a potential return date for either player.

"I think we're going to have some kind of end-of-week assessment, see where those guys are at and we'll continue those on in the next week," he said. "When the time is right to get those windows opened up, we'll do that, and get those guys back practicing again. But for right now, our focus is solely on Sunday in Atlanta."

Lowry out; Reed, Nailor could return

The Vikings listed defensive lineman Dean Lowry as out for Sunday's game because of the groin injury that caused him to miss a third day of practice Friday. O'Connell said linebacker Brian Asamoah II would be questionable with an ankle injury.

Guard Chris Reed and wide receiver Jalen Nailor are both questionable for the game, as well, though the Vikings would need to make a roster move to activate either player. Reed has been on the non-football injury list since training camp because of a stress fracture in his right leg, while Nailor has been on injured reserve since Sept. 21 because of a hamstring injury.