The Capitals, in their final regular-season visit to the Meadowlands Arena, dropped a 5-1 decision to the New Jersey Devils on John MacLean's hat trick.
With 16 games left for both clubs, the Capitals trail the fourth-place Devils by five points.
Caps coach Terry Murray said: "Oh, it's very important. As I said before the game, this is a must game for us. We've got to come out and get two points against the New Jersey Devils. Our schedule isn't too bad. We've got 10 games at home in the month of March. If we get too far behind the 8-ball, those games don't start meaning a whole lot."
A loss to the Rangers at Madison Square Garden tomorrow would put the Caps in a deeper hole despite the advantages given them by the schedule.
Washington plays 10 of its final 15 games at home, but did little against the Devils to show it can rally in the final weeks.
The Caps were careless in their zone and lacked sharpness in their attacks. The goaltending failed to cover these weaknesses.
The decision ended the Caps' four-game unbeaten streak against Patrick Division clubs.
Murray said: "The intensity wasn't there the way I would like it to be, that's for sure. I think when you start playing three in four nights, you're going to end up paying the price, and it looked like tonight we did pay the price."
Defenseman Al Iafrate said: "We were never in it. It's bad to see happen. You're running out of time and the team comes up that flat. I guess that's the excuse we got to use: We came up flat.
"You can't wait until there are three games left. Hindsight is 20-20. You look back and say, 'If we had only come to play this game or that game.'
"There's no way to explain what happened tonight. There are 20 different guys and you got to get them clicking. Maybe our team is fragile. I don't know."
Kelly Miller said: "It's easy to be negative. We didn't play very well tonight, but we're certainly not out of it. Five points down, that's not too much to pick up in a week."
The game included two major penalties, one by Kent Paynter on Claude Lemieux in the second period, and the other by the Devils' Brendan Shanahan on Peter Bondra.
If there was any good news for the Caps, it came from John Druce, who scored for the second straight game.
Only that goal prevented New Jersey's Chris Terreri from picking up his second shutout of the season.
But Terreri didn't have to work very hard. Washington didn't register a shot on goal until 5 minutes, 39 seconds of the first period, and had only two shots until a late-period power play.
In watching the first 40 minutes, you would never guess the game's importance to the Caps. Not only were they outscored, 5-1, and outshot, 26-15, but they also allowed a short-handed goal.
They also lost Paynter to a major penalty and had goalie Jim Hrivnak driven from the net.
Murray said: "We've got to get some big stops. Even though Jimmy Hrivnak is a young goaltender and up for only the seventh game he's played this year, he's got to give us bigger stops than what he did tonight. It didn't happen."
Mikhail Tatarinov's game symbolized Washington's struggle. He was on ice for four New Jersey goals in the first 40 minutes, and actually had the crowd laughing at him late in the first period.