Forward Derek Ryan also tested positive, and neither participated in practice, with Tippett telling reporters that the two were scheduled for another test later Tuesday, and the struggling team will just have to "see where they're at."
On Wednesday, Edmonton officially placed McDavid, Ryan and defenseman Tyson Barrie on the NHL's COVID-19 protocol list, prior to the team's game vs. the Toronto Maple Leafs, and also moved forward Ryan Nugent-Hopkins to injured reserve. Nugent-Hopkins had been day to day since Saturday with an undisclosed injury.
The absences surfaced immediately. Ilya Mikheyev scored the tiebreaking goal on a power play in the third period, and the Maple Leafs doubled-up on Edmonton 4-2, handing the Oilers their 11th loss in 13 games.
The Oilers have now returned from the league's COVID-19 pause and holiday break with five straight losses, all on the road. On Monday, Edmonton lost 4-1 to the New York Rangers, leaving Tippett quite frustrated.
"With the way things are going here, it's a daily occurrence," he said. "When you're playing in as many cities and there are different rules everywhere you go -- New York City there's one rule, on [Long] Island there's another rule, in [New] Jersey another rule -- it's crazy.
"They just tell me if he's positive, then he's positive. When two of your four centermen are out and one of them is Connor McDavid, that's not a positive."
Though Edmonton still has plenty of skill up front to compete, McDavid's absence is glaring, especially with the club searching for wins. He leads the team with 53 points and is second only to teammate Leon Draisaitl (26) in goals at 19. Draisaitl scored in the loss to Toronto, along with Brendan Perlini.
McDavid, a fixture on one of the league's most lethal power plays, has five goals this season with the man advantage, and is averaging 22:30 time on the ice.
Against the Rangers, Edmonton could only muster a lone goal, from unheralded center Ryan McLeod, in falling into a 2-8-2 stretch over their last 12 games.
Edmonton, fueled by hot starts from McDavid and Draisaitl, began the season 16-5-0.