Through 11 weeks, no NFL offense has scored more touchdowns than the Vikings when within the opponent's 20-yard line. But the NFL's No. 1 red-zone attack could be without its top red-zone target on Sunday against the Panthers because receiver Adam Thielen is uncertain to play while quarantined.

Thielen, who leads the NFL with a career-high 11 touchdown catches in 10 games, must test negative for the coronavirus to build on his stellar start. He was placed on the COVID list on Monday after a reported positive test. Further daily test results will determine his availability for Sunday, according to coach Mike Zimmer, indicating he's asymptomatic because symptomatic cases require a 10-day isolation and would rule him out against Carolina.

If asymptomatic, Thielen can return with two negative tests taken within five days of his positive test.

"I don't know, honestly," Zimmer said Wednesday when asked of his expectations. "He's in the COVID protocol, and we'll just see. When you get in these protocols, it's always about, 'What's the next test, and the next test?' So we'll just have to see as the week goes on."

Quarterback Kirk Cousins said Thielen's absence is part of "managing the virus," but the NFL's protocols haven't yet taken away a Vikings player of Thielen's caliber. Two others, linebacker Todd Davis and guard Dru Samia, missed games because of positive tests.

Thielen, the Vikings' veteran among a young receiver group, has led on and off the field, pacing the offense in catches (49), targets (76) and receiving touchdowns while rookie Justin Jefferson leads with 848 receiving yards.

"We've had other people out during practices and tried to change things," Cousins said. "That's just been kind of part of managing the virus. Obviously, you deal with injuries, too. We had lost Adam last year as well for several weeks, so it's just kind of part of the process of going through the season."

Replacing Thielen's vise-grip hands might be the toughest what-if to tackle. He's a go-to option when space is tight. Thielen has 11 of Cousins' 20 touchdowns, in part because Cousins often looks to him when the Vikings are near the goal line.

Seven of Thielen's touchdown grabs have been thrown within the 10-yard line, including three scores while a defender was flagged for holding him in the end zone. Cowboys cornerback Anthony Brown illegally grabbed Thielen before the spectacular one-handed touchdown grab during Sunday's 31-28 loss.

"He's sure-handed," Jefferson said. "He's able to make those hard catches that you have to adjust to. He can also get his two feet in the end zone as well, so he's got the toe tap."

The Vikings went 4-1 last year while Thielen was out because of a hamstring strain. His potential absence this year would pose even bigger questions if not for Jefferson, who has helped the Vikings offense transition seamlessly after trading away a star in Stefon Diggs this offseason.

Jefferson, leading a heralded rookie class in receiving yards, has Panthers coach Matt Rhule's attention ahead of Sunday's game at U.S. Bank Stadium.

"He's special. He's going to be a great player for a long time," Rhule said. "He's a deep-play threat who's also a great route runner. I think that's the special thing about him. You can find guys who can run downfield and push upfield, but he can do both."

If possible, coordinator Gary Kubiak could lean even more on running back Dalvin Cook with more targets. Or he could further spread the ball around with tight ends Irv Smith Jr. and Kyle Rudolph, as well as fullback C.J. Ham, involved in the play-action passing game.

Receiver depth is still lacking. With Jefferson looking ready for a No. 1 role if needed, that leaves Chad Beebe, Bisi Johnson and Tajae Sharpe as the most experienced options. They've combined for 13 catches and 165 yards this season.

"Beebe's come in and done a nice job," Zimmer said, "and Bisi Johnson's had some opportunities. We'll just keep going. Obviously, Jefferson is terrific. We'll figure out ways to go if that's the case with Adam."