The Vikings got good news: Everybody was cleared Thursday to practice for the first time for Sunday's game in Houston.

No Vikings coaches, players or team personnel have tested positive for COVID-19 after last weekend's game with the Titans, who have now had 12 people test positive since Saturday.

The Vikings were cleared by two rounds of testing — Wednesday's PCR tests and rapid-response tests on Thursday morning — before returning to work and ending the two-day closure of TCO Performance Center.

An extended morning walk-through and afternoon practice Thursday was part of coach Mike Zimmer's way of trying to "get in everything that we normally get in" to prepare for the Texans. Wednesday's practice was canceled and Tuesday's game-planning meetings were moved online after the league abruptly told the Vikings to evacuate their headquarters when it learned of eight positive tests on the Titans on Tuesday morning.

Vikings coaches met with players virtually throughout the offseason, but they had settled into on-field work in person since late July. All team meetings must continue to occur virtually, according to an NFL memo sent to teams Thursday night detailing coronavirus protocol changes that exposed teams such as the Vikings must follow.

"It's been challenging, let's be honest," offensive coordinator Gary Kubiak said Thursday. "Trying to get our work done, trying to get our computers moved, trying to get all our stuff and our preparation ready for the players, it's been a challenge.

"I'll say this, the players have been great. Zim has found a way for us to get that done and we're catching up [Thursday]. It's just part of the process. I think everybody knew we were going to face some things like this."

Workdays are starting a little later because of additional testing. Coaches, players and staffers will continue to take rapid-response tests, which are considered less accurate than 24-hour PCR tests but take about 20 minutes to process, before entering TCO Performance Center as part of enhanced protocols established in the wake of the Titans' outbreak.

Gloves and masks, or face shields affixed to helmets, must now be worn by players on the field during practices. Quarterbacks are the only players not required to wear a glove on their throwing hand. The weight room will be limited to 10 players at a time, and no team gatherings are permitted away from the facility.

The Vikings will also have PCR and point-of-care tests before kickoff Sunday; game days are the only day the NFL isn't normally testing players or personnel.

The league postponed the Titans' Week 4 game against the Steelers "to later this season" after a fifth Titans player — cornerback Kristian Fulton, who played against the Vikings and had a sack in 25 defensive snaps — and another staffer tested positive Thursday morning. It is the first postponement related to COVID-19 of the 2020 season.

It will likely be a few more days before the Vikings know whether any players contracted the virus as a result of exposure to the infected Titans players and staffers.

Results from tests taken Thursday, Friday and Saturday remain critical for the Vikings' outlook, according to athletic trainer and the team's infection control officer Eric Sugarman. The incubation period of COVID-19 can last up to two weeks, according to the CDC, but generally appears on a test by at least three to five days after contact, Sugarman said.

For any competitive disadvantage concerns, the Vikings have been told by the league there's already precedent for teams being short a practice or two because of a natural disaster and still having to prepare for kickoff. The Texans practiced Wednesday, when quarterback Kirk Cousins and his Vikings teammates found themselves with extra down time after virtual meetings.

"It was a little off when we finished up [Wednesday]," Cousins said. "There was just a little bit more time because of not hitting the practice field. Trying to figure out how to best use that time was just a different day all around. Still productive, and fortunately we are back in the building now. [Wednesday], we didn't know if that would be possible."

Without any positive cases connected to the Titans outbreak at this point, the Vikings' situation could be worse. But they won't be able to make up for losing an entire day on the field. Cousins said players can only "do the best you can" under whatever circumstances 2020 brings.

It's another curveball as the 0-3 Vikings are scheduled to play in front of a possible 13,300 fans at NRG Stadium in Houston, which will allow 20% capacity for Sunday's home crowd.

"It's been a different week," co-defensive coordinator Adam Zimmer said. "We're trained for it now because we've done it so much in the past. It wasn't that much of an adjustment with the guys, they know how it goes with the virtual meetings and virtual walk-throughs that we've had to do. So at least we've been able to do it in the past and it's not completely foreign to us."