Capitals center Cody Eakin, left, pushes his way past Sabres defenseman Jordan Leopold. (Toni L. Sandys/WASHINGTON POST)

The Washington Capitals’ ambitions do not lie in September. But the rally they put together in Friday night’s preseason game against the Buffalo Sabres could boost the confidence of a team still working out the kinks of a lineup with five new faces.

Using their most complete roster of the preseason, the Capitals needed a shootout winner by Nicklas Backstrom to defeat the Sabres, 4-3, at Verizon Center. It wasn’t the prettiest or most polished performance, but Washington managed to weather some of its early miscues to capture a second exhibition win.

For the first time in the preseason, nearly all of the Capitals’ NHL regulars were in the lineup, with the exception of veteran right wing Mike Knuble, who was given the day off after appearing in two games this week. That group featured all five of Washington’s free agent signings from this offseason and there is bound to be an adjustment period as players learn each others’ tendencies at game speed rather than in practice.

That unfamiliarity, however expected at this time of year, led to some breakdowns. Passes weren’t always on the mark, players accidentally went offsides and, most notably, there were hiccups on defensive positioning and in the reaction to some of Buffalo’s rushes up the ice.

“I think on the [three] goals that were scored against us there’s still the newness of communication between Tomas [Vokoun] and the defense,” Boudreau said of his starting goaltender. “I think on . . .those goals — we talked about it in between periods — there was a miscommunication. Whether it was handling the puck, or letting it go. Defense in front — ‘Should I block, should I not?’ Once we got that straightened around, I thought they played a really good third period.”

Vokoun finished with 21 saves and four stops in the shootout, and some of the Capitals’ prominent offensive stars began to shake some of the cobwebs off. Washington took the initial lead 8 minutes 6 seconds into the game on Backstrom’s first goal of the preseason but 20 seconds later, Jason Pominville tied it up at 1. Buffalo took a 2-1 lead with less than three minutes remaining in the opening period when a shot was tipped in by Tomas Vanek.

The teams exchanged goals again in the second, this time Mike Green notching his first goal of the preseason. Green’s tally — which came during a ruckus around the net on a power play midway through the period — might actually have been scored by Alex Ovechkin, both Green and Boudreau noted after the game, but there’s no replay in the preseason. After Green’s goal, though, there was a series of breakdowns by the Capitals that yielded scoring chances for Buffalo, and Vanek cashed in again with just more than six minutes remaining in the period.

“I think the D-zone is the most important thing for us,” said Ovechkin, who had two assists. “We all know we’re good offensively, but every time you have to play more careful in your zone. So we just give more attention to details in the D-zone.”

After recording 15 shots through the first two periods and falling into a familiar habit of looking for the perfect play rather than the available one, the Capitals switched gears in the third. The forecheck came out with more grit and Washington dictated play in the final 20 minutes, outshooting Buffalo, 15-3, and tying the contest on a goal by Matt Hendricks with 6:27 left.

“I think we got over our mistakes in the first couple periods, sustaining forechecks and making their D-men turn and getting pucks behind them,” said Troy Brouwer, who added two assists. “We came in, we talked about it and realized that dangling and turning pucks over at the blue line isn’t what we need right now. We need to get pucks deep and establish a forecheck and we’ll have success.”