The Vikings will be retesting more vaccinated employees through the morning of Sunday's game in Los Angeles as close contacts after defensive end Kenny Willekes became the sixth player Friday isolated on the reserve/COVID-19 list since Nov. 4.

Willekes did not practice Thursday because of an illness, indicating he was the latest to test positive as the Vikings have taken extra precautions this week to mitigate the internal spread of the virus. They started the week Monday by retesting 29 players, coaches and staff members — including coach Mike Zimmer — and will be retesting more after the latest case. Some have already been cleared through negative tests.

"Some of them are out of it now," Zimmer said Friday, "and some more are added on because of close contacts."

None of the six players on the COVID list will be cleared by Sunday. That list includes safety Harrison Smith, center Garrett Bradbury, guard Dakota Dozier, linebacker Ryan Connelly and tackle Timon Parris. Those deemed close contacts are still permitted to travel with the team to Los Angeles, so long as they're vaccinated and haven't tested positive.

Bradbury, the first player to test positive Nov. 4, was eligible to return but still had not tested negative as of Friday morning. He will miss a second game. One Vikings player — identified by multiple sources as the vaccinated Dozier — remained hospitalized as of Thursday evening, according to Zimmer, after being admitted on Tuesday night due to breathing problems amid his COVID-19 infection.

"He's doing a lot better," Zimmer said.

Only further testing will determine the extent of the virus' spread within the team. Under NFL protocols, vaccinated individuals are tested weekly. If they're identified as close contacts or exhibiting symptoms, they're subject to daily testing for five days.

All coaches and staffers working on-site at TCO Performance Center are vaccinated. But players are not required to be vaccinated, which was collectively bargained with the players' union. Unvaccinated players are tested daily; that's how Smith tested positive hours before kickoff of last week's loss in Baltimore.

The Vikings re-signed defensive end Eddie Yarbrough to bolster depth at a position that keeps taking hits. Yarbrough, 28, was most recently on the 49ers practice squad. He joins defensive ends Everson Griffen, D.J. Wonnum and Patrick Jones on the active roster. Willekes was the first man off the bench after the Danielle Hunter injury, and now those reps will fall to Jones — the third-round draft pick who has played just six snaps — and Yarbrough.

Yarbrough had eight tackles in four games for the Vikings last season, experience that coaches hope enables him to help the shorthanded defense just two days after re-signing.

"That's what we're thinking," Zimmer said. "We're trying to get him caught up to speed as fast as we can."

Barr, Pierce still sidelined

Against the Chargers the defense will also be without linebacker Anthony Barr (knee) and nose tackle Michael Pierce (elbow) due to injuries. Neither were spotted at the start of Friday's practice inside the fieldhouse at TCO Performance Center. Cornerback Bashaud Breeland (groin) is listed questionable despite practicing every day this week.

Barr, who had the overtime interception while playing all 98 defensive snaps against the Ravens, will miss another game due to the nagging knee injury that first arose in August. This is his fifth absence after starting the past four games.

To live and play in L.A.

Linebacker Nick Vigil will replace Barr as an every-down linebacker against his former team. Vigil appeared in 15 games for the Chargers last season before signing a one-year deal with the Vikings this spring.

"I'm excited," Vigil said. "I know a lot of people there, have a couple of good buddies on the team. So, it will be good to see everybody, and the stadium's awesome, so it will be fun to play there."