On Thursday night, the Capitals look for their fifth consecutive victory as they host a Blues club that's dropped four in a row.
Washington (19-10-3) returns to the Verizon Center following a 5-4 overtime win over the New York Islanders on Tuesday. Alex Ovechkin scored two goals, including the winner with 10.7 seconds left, as the Caps won for the sixth time in seven games.
Washington was outshot 17-5 in the third period as it let a two-goal lead slip away.
"We didn't play well enough last night. We didn't respect our opponent, and we didn't play hard for the entire game," general manager George McPhee said Wednesday. "You could see early in the game that we had a couple of players that were playing far too cute. It was our grinders that got us through. We expect and demand a lot from these guys now."
Since losing back-to-back games from Nov. 29-Dec. 2, the Caps are 6-1-0 while outscoring their opponents 23-13.
St. Louis (12-15-3) is among the league's worst defensive teams, allowing an average of 3.33 goals this season, including 5.25 during its four-game slide.
Ovechkin, who has five goals and two assists during Washington's winning streak, had a pair of assists in the Caps' last game against St. Louis -- a 4-3 road loss on Oct. 27, 2007.
Nicklas Backstrom extended his point streak to five games with two assists versus the Islanders. The second-year center has five goals and eight assists as Washington has won eight of 11.
Defenseman Mike Green assisted on Brooks Laich's first-period goal Tuesday, giving him a goal and three assists in three games since missing 11 with a shoulder injury. He scored twice in last season's loss to the Blues.
After sitting out Saturday's 2-1 victory over Montreal with a sore hip, Brent Johnson won his fifth straight start Tuesday by stopping 35 of 39 shots. He has a 1.77 goals-against average during that stretch.
Johnson, who was 76-47-0 with 12 ties in four-plus seasons (1998-99, 2000-03) with St. Louis, gave up four goals on just 18 shots in last season's loss to the Blues -- his only career appearance against his former team.
While Washington looks to improve to 13-1-1 at home in 2008-09, the Blues are looking to break a four-game road losing streak.
St. Louis is coming off a 6-3 home loss to Calgary on Tuesday that followed an 0-3-0 West Coast trip.
Since defeating Nashville 6-3 on Dec. 8, the Blues have been outscored 21-11 in their last four games.
"When you're giving up five, six goals a game, it's hard to win," defenseman Barret Jackman said.
Chris Mason's struggles continued on Tuesday as he allowed six goals on 31 shots. He's 0-5-1 with a 4.45 GAA in his last six appearances.
Offensively, Brad Boyes has been the Blues' major threat. The right wing, who had a goal and an assist against the Flames, has six goals and seven assists in his last 10 games.
Boyes scored twice in St. Louis' win against the Capitals in 2007-08.
In the teams' last meeting in Washington, the Caps won 5-4 in a shootout on Jan. 19, 2006.