Washington can clinch the Southeast Division title with a victory, which would in turn be a crucial blow for Winnipeg's chances.
The Capitals (25-18-2) have won 13 of their last 16 and sit a point ahead of the Jets (24-19-3), who have won six of seven and trail Ottawa and the Rangers by a point for the final playoff spot in the Eastern Conference. Washington also has a game in hand on Winnipeg.
Alex Ovechkin scored two goals in the Capitals' 5-1 win at Montreal on Sunday in their road finale, and now has 10 in his last eight games. Troy Brouwer also remained hot with two goals, pushing his total to six over the last five contests.
"I'm pretty happy I scored some goals and we won the game," said Ovechkin, who has scored at least 30 goals in each of his eight seasons and eyes his third Rocket Richard Trophy as the league's top goal-scorer. "But we still have three games left to play and the next one is the biggest game of the year."
The Jets appeared to have little chance in the playoff race not long ago, but they've followed a five-game skid with a 6-0-1 stretch. They hadn't gone seven straight with a point since another 6-0-1 run from Nov. 22-Dec. 5, 2006, when they were the Atlanta Thrashers.
Antti Miettinen scored with 7:36 left to lift Winnipeg to a 2-1 win at Buffalo on Monday, the first time during the point streak the Jets had scored fewer than four goals.
They took little time to enjoy the victory, however, with a clear focus on taking a step toward the franchise's second postseason appearance.
"This game means nothing now," said Evander Kane, third on Winnipeg with 32 points. "We needed this game in order to make something of (Tuesday). (Tuesday is) the biggest game of our season."
Washington has scored five goals in three of its last four games and its power play continues to click. The Capitals have seven goals on 21 chances over their last five and also haven't allowed a man-advantage goal in four games while killing off all 13 of their opponents' chances.
The Jets have won four of the teams' last five meetings in Washington, including the season's first meeting. The Capitals won three in Winnipeg after that while outscoring the Jets 13-1.
Washington is 2 for 16 on power-play opportunities in the season series while Winnipeg is 3 for 14.
"It's their season and it's our season," Capitals defenseman Jack Hillen told the team's official website. "It's a playoff game (Tuesday). I expect the building to be rocking, the fans to be rocking. I think it's going to be one of those games that you relish as a player, one of those fun games.
"Throughout the course of the regular season, sometimes there are games where you've just got to get your body up and get through them. But this is one of those games where you're ready for it; you're up."
Ovechkin had seven points in the first four meetings and has 76 in 52 career games against the Jets/Thrashers franchise.