Heading into Monday night’s game in Ottawa, the St. Louis Blues were riddled with newly discovered injuries. But more bad news could be coming to the Central Division squad after the 3-2 overtime loss.

With defenseman Jordan Leopold out of the lineup since Nov. 7 recovering from hand surgery and tough-guy Ryan Reaves recouping from a broken hand suffered on Nov. 23, the Blues learned Monday morning that they would be without the services of forwards Vladimir Sobotka and Jaden Schwartz. Both skaters sat out the morning skate, nursing upper-body injuries.

“They’re both banged up like a lot of guys on our team,” coach Ken Hitchcock told Jeremy Rutherford of the St. Louis Post-Dispatch before the game against the Senators. “‘Sobi’ obviously didn’t finish the (Columbus) game and ‘Schwartzy’ was tired at the end and didn’t play very well in the third period because he was just exhausted.”

Hitchcock inserted winger Magnus Paajarvi and the recently recalled Chris Porter into the lineup. Paajarvi started the game on a line with Patrik Berglund and Vladimir Tarasenko while Porter found himself on the fourth line with Maxim Lapierre and Adam Cracknell. But after the Blues found themselves outplayed and facing a 1-0 deficit through one period, the lines were switched up and both players found themselves playing with a heap of different players.

The line shuffling continued after Chris Stewart tied the game in the second period, but not because of poor play.

Captain David Backes, who scored the game-winning goal in overtime against the Columbus Blue Jackets just two nights prior, left the game with an apparent upper-body injury with 2:49 remaining in the second period. It occurred after he was the recipient of an open-ice hit from Senators left-wing Colin Greening, causing him to skate awkwardly to the bench and into the Blues’ locker room after stumbling into a stick rack alongside the runway.

Stewart added another goal with 13 seconds remaining in the same period to give his team the lead before Ottawa’s Bobby Ryan knotted it up at 5:44 of the third period. Defenseman Cody Ceci notched his first NHL goal in overtime, only allowing the Blues to record one of a possible two points in the standings.

Backes has been the center on arguably the NHL’s best line to open the season. He and linemates T.J. Oshie and Alex Steen have combined for 42 goals and 92 points through 32 games. The three have accounted for 37.5 percent of the team’s goal output thus far.

Backes has already eclipsed his totals from last campaign, recording 16 goals and 30 points. He had just six goals and 28 points in 48 games in the 2012-13 season. He also ranks second on the team with a 51.4 percent in the faceoff circle. The other injured Blues center, Sobotka, is first with a 61.8 percent in the dot.

The Blues now shift their focus to Tuesday night, when they host the San Jose Sharks at Scottrade Center. The Blues are 0-2-0 when facing the Sharks this season, being outscored 12-5 in the process.

There has not been an official word on Backes’ condition. For the Blues’ sake, the hope is that it will be a short-term recovery.