No Vikings players are on the team's COVID list after second-year tackle Oli Udoh was cleared to return on Thursday.
The Vikings, at one point, had eight players on the COVID list during entry testing. Leaguewide positive rates have remained low, and revised protocols aim to curb "false positives."
Defensive tackle Armon Watts told the Star Tribune that his two-day stint on the list last week was because of a "false positive."
Now, a player who tests positive but is asymptomatic with no known history of infection can return after two confirmatory tests are negative.
"I had a false positive on one of my tests," Watts said. "So I haven't had it. I'm sure guys will have their concerns [about coronavirus], but the Vikings are putting us in a good situation and keeping us safe in the building and out at practice. We feel pretty safe."
NFL teams will continue to test players and staff every day at least through Sept. 5.
Udoh, who spent two weeks on the reserve/COVID-19 list after testing positive for the virus July 29, rejoins the team just before Friday's first full practice of training camp. Padded sessions can begin Monday.
Linebacker DeMarquis Gates was waived to make room on the 80-man roster.
Andrew Krammer and Mark Craig contributed to this report.