In these playoffs, the trio of Mike Knuble, Keith Aucoin and Joel Ward has been the Washington Capitals’ “fourth” line in name only.

The unit has combined to score three goals in the past six games, including Mike Knuble’s in Monday’s 3-2 victory over the New York Rangers. With two of those three tallies, Knuble is now tied for fourth on the team, despite ranking last in average ice time per game (8 minutes 46 seconds).

Talk about efficiency.

“We’ve been playing well,” Knuble said. “First and foremost, we’ve been good defensively. We haven’t been a thorn in our side, a hindrance to the team’s defense. And at times when we haven’t scored, we’ve been able to rag the puck around and make guys play in their own end. We’re not going out there thinking we’re going to score. So it’s a huge bonus when we do.”

In Game 2 at Madison Square Garden, they notched another one of those enormous bonuses.

The play began with Ward picking off a careless defenseman-to-defenseman pass by New York’s Stu Bickel. Ward controlled the puck and raced the other way, flanked by Aucoin and Knuble on a fast-developing three-on-two advantage.

Once in the Rangers’ zone, the three forwards completed a sequence of passes not normally seen from checking-line players. Ward passed to Aucoin, who quickly returned to the puck to Ward at the side of the net. Without hesitation, Ward zipped a pass across to Knuble, who slipped past Rangers’ defenseman Michael Del Zotto and tapped the puck past Henrik Lundqvist.

The goal put the Capitals ahead, 1-0, and halted the momentum New York had been building in the minutes leading up to it.

“You could hear the bench screaming that there were three of us,” Knuble said. “It was a great passing play. Wardo sent a rocket right across the crease, right onto my tape. It was good way to relieve the pressure, because I think they were coming on a bit.”

Ward added: “I saw the D-man had the puck and I saw Knubes start to pressure. I just stepped up there and I had a feeling he was going to throw it across and he did. I just happened to intercept it.”

The Ward-Knuble connection, of course, is the reason the Capitals are still playing. In Game 7 against Boston, Ward backhanded a Knuble rebound past Bruins goalie Tim Thomas in overtime. In Game 5, Ward set up Knuble for a pivotal third-period score.

In fact, it could be argued that the fourth line has been the Capitals’ best in the postseason. And it’s happening to a trio of players who, at different times this season, had plenty of reason to doubt themselves.

Aucoin, 33, spent the first two-thirds of the season playing for the Capitals’ minor league affiliate in Hershey, Pa. Ward, 31, was a healthy scratch seven times down the stretch. Knuble, 39, also spent his fair share of games in February and March wondering when he’d return to the lineup.

Coach Dale Hunter discovered the line’s chemistry late in the regular season and used it intermittently in March and April. Hunter then reassembled the unit in Game 4 against Boston when Knuble, a healthy scratch to start to the playoffs, was reinserted into the lineup.

There’s been no looking back.

“They’re easy to play with,” Ward said. “Coiner’s got a good stick and makes plays. Knubes is going to take the puck to the rack, is a big body, is obviously very smart and good along the walls. That complements myself because I want to take pride along the walls, too.”

One thing the entire line can beam about is its strong play defensively. They sport a combined plus-minus rating of plus-7.

“We work well together in the offensive zone and the defensive zone,” Aucoin said. “We’ve had a lot of really good chances and we hadn’t capitalized on them. Tonight we did.”

The only downside to scoring so frequently, Ward joked, is that they can no longer fly under the radar.

“We don’t want the attention,” he said with a chuckle. “We just want to go about our own business, sneak in through the back door and chip in. And that’s what we’ve been doing.”