Wednesday's retests confirmed that the originals were in error, the league said, and all players involved were made available for their next games.
For the Blues, that meant Wednesday night against the Colorado Avalanche for Game 2. Though the names of St. Louis' players involved in the retesting were not released, there were four Blues -- Jaden Schwartz, Vladimir Tarasenko, Marco Scandella and Jordan Binnington -- who missed the morning skate on Wednesday. All four were on the ice for pregame warm-ups in Denver, and they played in Game 2, a 6-3 St. Louis loss.
"Those reported results emanated from the same laboratory, and due to other peculiarities and similarities as among the test results themselves, an investigation was initiated into the possibility that the initial test results reported may have been in error," the league said in a statement. "All affected players were immediately isolated and further testing was done involving collected samples. Those tests have returned uniformly negative results, therefore confirming that the initial reported test results were in error. As a result, all affected players will be eligible to play in their team's next game."
The Blues were without forward David Perron, their leading scorer, for Game 1 because of protocols. Forward Nathan Walker and defenseman Jake Walman also were on the list. They did not dress for Game 2.
Walman was a notable absence because the Blues said he was the rare "breakthrough case" of COVID-19 after vaccination. He was placed on the list May 12 after the team asked for additional testing.
The Golden Knights and Minnesota Wild will play Game 3 of their first-round series on Thursday. That series is tied 1-1.
There is still consistent testing of players in the Stanley Cup playoffs, but the NHL announced earlier in May that it would be easing COVID-19 restrictions for U.S. teams once 85% of each traveling party was fully vaccinated. Those teams could have players gather in groups and not undergo PCR (polymerase chain reaction) testing on off days, among other perks.
Well over 100 NHL players missed time in the regular season after going on the NHL's coronavirus-related absences list. Multiple teams had their seasons interrupted by COVID-19 outbreaks, including the Vancouver Canucks, who finished their regular season on Wednesday with a loss to the Calgary Flames.