The Blues will be without forward Robert Thomas when they host the Central Division-leading Dallas Stars on Monday night.
Coach Craig Berube said Thomas suffered a lower body injury in the third period of Saturday's overtime win over the Florida Panthers and is day-to-day.
"He's a huge loss, for sure," Berube said. "From a guy who probably has the most puck possession on the team every night and has the puck a lot and does good things with it. Guys are going to have to dig in tonight and help out."
Thomas leads the team with 19 points (four goals, team-high 15 assists). Ivan Barbashev is expected to take his spot on the second forward line and center Pavel Buchnevich and Vladimir Tarasenko, which means the Russian Line would be reunited.
Brayden Schenn, who, like Thomas, left Saturday's game early, skated Monday morning and will play against Dallas. Defenseman Justin Faulk was not at the skate because his wife had had a baby that morning, but Berube said Faulk would play Monday night.
Also on Monday, a couple of young Blues forwards traded places when Jake Neighbours was recalled from the club's AHL affiliate in Springfield and Nikita Alexandrov was assigned to the Thunderbirds.
Alexandrov was a healthy scratch in the win at Florida as Berube opted for a lineup featuring 11 forwards and seven defensemen. The 22-year-old has one assist in nine games with the Blues this season, and eight points (four goals, four assists) in nine games with the Thunderbirds.
Neighbours, 20, scored a goal in St. Louis' season opener but did not register a point in his next 10 games before being assigned to Springfield, where he's tallied five assists in seven games.
Neighbours, a first-round draft pick in 2020, is expected to play on the third line with Brayden Schenn and Jordan Kyrou against the Stars. "We'll need his energy and his game tonight," Berube said.
Coverage begins at 6:30 p.m. on Bally Sports Midwest.