Schenn has been dealing with an upper-body injury and last played on Dec. 12 vs. Anaheim.
During Tuesday's team practice, the 30-year-old was skating on the left side with Ivan Barbashev and Pavel Buchnevich, which is where he's expected to play Wednesday.
"I thought the way (Robert Thomas) and (Jordan) Kyrou and (Vladimir) Tarasenko have been playing, I didn't want to move that line," said Blues Head Coach Craig Berube. "And (same) with the (Ryan) O'Reilly line. It was a good spot for Schenner to go in with Barby and Buchy.
"I think (Schenn) has had success in both (center and wing)," Berube added. "He's moved from wing to center and center to wing pretty much his whole career. Right now we'll start him here and go from there."
The only player the Blues don't have available to play is Robert Bortuzzo, who is still out due to COVID-19 protocols. Berube said Bortuzzo should be available to rejoin the team for its next practice, which would likely be on Thursday.
"It's nice to have everyone back," said Robert Thomas. "It's always nice when everyone is healthy. It's definitely a positive. I think for all of us going at the same time, feeding off each other, I think we can be pretty dangerous. I think we've got three lines that can score - all of them could be first lines."
Below is a projected lineup for Wednesday's game against the Penguins:
