Rantanen was placed in COVID-19 protocol Tuesday but has not tested positive for the virus, according to coach Jared Bednar.
"He got contact traced, so he can't come with us on the trip," Bednar said Wednesday. "He has to continue to get tested here for a little bit, and then there's a possibility he can meet us and be an option for us before the trip is over."
The Avalanche who could have clinched a berth in a Stanley Cup Playoffs with a regulation win, had not played since a 4-3 win at the Blues on April 14. The NHL announced Friday that three Colorado games (against the Los Angeles Kings on Friday and Sunday, and at St. Louis on Tuesday) were postponed because of a third player testing positive, forward Joonas Donskoi.
The other two positive tests at the time were goalie Philipp Grubauer, who was placed in protocol April 14 and will be out at least one more week, and defenseman Bowen Byram, who had been on the list since April 9.
Byram came off the list Monday but did not travel with the Avalanche to St. Louis. The rookie has not played since March 25, missing seven games with an upper-body injury before being placed in protocol.
"He's in that window of just still trying to make sure he's cleared to get on the ice and join full-team practice ...," Bednar said. "And all the guys who tested positive for COVID are doing well. They're feeling good. Some guys went through minor symptoms but they're all feeling good and just sort of putting in their time right now before they can join us."
The Avalanche were tested for COVID-19 before they returned to practice Wednesday.
"Today's energy level, I would rank it as just OK," Bednar said. "I didn't think the ice was very good, the guys hadn't been on, so they were rusty. We started out OK, and then we petered out pretty quick. Hopefully that's something we can get back quickly. I know the guys were working out, doing what they can on their own, but what they can do is sometimes limited, depending on the resources they have. … We're just going to have to grind through and hopefully get a real smart, intelligent game from our guys tomorrow."
Colorado was scheduled to play at St. Louis on Thursday, Saturday and Monday, and at the Vegas Golden Knights on April 28 before returning home to play the San Jose Sharks on April 30. Colorado was scheduled to play at Vegas on Monday; that game has been moved to May 10.
Rantanen was second on the Avalanche with 52 points (26 goals, 26 assists) in 43 games, one point behind linemate Nathan MacKinnon (17 goals, 36 assists in 39 games). Rantanen, Donskoi and Grubauer remained in COVID-19 protocol Thursday.
"You miss guys and you just have to bear down and play the game and get your points," forward Pierre-Edouard Bellemare said. "Missing guys [stinks], you never want to see one of your teammates not being there. The COVID situation is kind of the new normal.
"This whole season is a little bit odd this way, but there's nothing you can do about it. You just wake up, come to the rink and do your job as best you can."
Defenseman Patrik Nemeth played Thursday, his first game with Colorado since being acquired in a trade from the Detroit Red Wings on April 9.
The Avalanche (30-9-4) were second in the eight-team Honda West Division, four points behind the Golden Knights and three points ahead of the third-place Minnesota Wild. The Blues are fifth in the West, one point behind the fourth-place Arizona Coyotes. The top four teams will qualify for the Stanley Cup Playoffs.
The three postponed games were rescheduled: the games against the Kings are scheduled for May 12 and May 13, and the April 20 game against the Blues is the one being played Monday.
The NHL has postponed 53 games because of COVID-19 protocol since the season began Jan. 13.
NHL.com staff writer Tracey Myers contributed to this report
