Jake Allen's injury came at the tail end of St. Louis' worst stretch of the season and has kept the Blues' No. 1 goaltender out ever since.
Brian Elliott has been a solid replacement during the club's resurgence.
The Blues can win a season-high-tying fourth straight game by beating the host Colorado Avalanche for the first time in three meetings Friday night.
Allen has 18 wins and a 2.17 goals-against average in 33 games, but he suffered a knee injury in the second period of a 4-3 shootout loss at Anaheim on Jan. 8 that capped an 0-2-3 stretch for the Blues (28-15-7).
In his previous start two days earlier, Allen came way out of his crease and failed to intercept a long outlet pass in overtime at Colorado, leaving John Mitchell to find Gabriel Landeskog in front of the empty net to give the Avalanche a 4-3 victory.
Allen could miss at least another week, but Elliott has been steady in six starts since Allen went down. He's 5-1-0 with a 2.03 GAA in that span after making 29 saves in Wednesday's 2-1 win over Detroit.
Ty Rattie and Dmitrij Jaskin scored for St. Louis, which is on the verge of winning four straight for the first time since Oct. 13-18.
"We're playing well, even if we're giving up a lot of shots," Elliott said. "When someone makes a big block, that makes a huge difference."
St. Louis has allowed 117 shots during the three-game win streak while managing 67 itself.
The Blues' run has come despite some uncertainty on defense. Carl Gunnarsson has been dealing with an upper-body injury and was expected to return against the Red Wings after missing the previous four, but it was determined shortly before faceoff that he wouldn't be able to go.
Colton Parayko was scratched because of an illness, leaving St. Louis with five defensemen. Both of their statuses are unclear for Friday.
"We had to change our defensive structure," coach Ken Hitchcock said. "We've done it three times in the last couple weeks, so we know how to adjust."
Allen was also in net when the Avalanche (24-21-3) beat the Blues 3-1 on Dec. 13. Elliott, though, is 5-1-0 with a 1.74 GAA in his last six against Colorado, which heads into this matchup having won three of its last four.
The Avalanche have won back-to-back 2-1 games, beating Winnipeg on Monday before Francois Beauchemin's deflected goal with 31.7 seconds remaining defeated Buffalo on Wednesday.
Alex Tanguay's goal tied it earlier in the third period to end a 26-game drought.
"It's been a tough year for me getting points, but I want to help this team make the playoffs and I know I've got better," Tanguay said. "We'll certainly take the points and get ready for Friday. We all see the standings. We all see where we stand. We all know how important the two points are."
Semyon Varlamov has done his part in the last two, stopping 63 of 65 shots after posting a 3.88 GAA while splitting his previous four starts. He's been in net for both meetings with the Blues this season, making 42 saves in the first and 35 in the second.
Vladimir Tarasenko scored in each matchup.
