Brock Nelson and fellow rookies delivered down the stretch and provided a glimpse at a brighter future for the Islanders, who head into the offseason after missing the playoffs for the sixth time in seven years.
Nelson scored with 3:44 remaining to force overtime, and then netted the lone shootout goal in a 4-3 win over the Buffalo Sabres on Sunday night in a season-ending matchup of non-playoff teams.
The Islanders (34-37-11) won by rallying from a 2-0 deficit and closed the season by winning three straight and eight of 12 (8-2-2).
''These kids have played extremely hard, and I'm proud of what they've done not only in the last month and a half, but these last three games,'' Capuano said. ''They really stuck together.''
The future looks even better after Capuano reiterated that Tavares is on track in his recovery from a left knee injury and should be ready to begin training in the summer.
There is much more work to do in Buffalo.
Torrey Mitchell, Jamie McBain and Matt Ellis scored for the Sabres (21-51-10), who had already clinched the NHL's worst record. The Sabres went 0-6-1 in their final seven games.
With 150 goals scored, Buffalo set the NHL-low in the league's post-expansion era that began in 1967. The previous low was 151 by Tampa Bay in 1997-98.
''The standard has to be set a little bit higher than it was,'' Sabres coach Ted Nolan said. ''We'll address that starting with the meetings (Monday).''
Nelson, an Islanders' first-round pick in the 2010 draft, was eager to show what potential the team's youngsters possess.
''We knew we had a young group and a lot of rookies,'' said Nelson, who topped the Islanders' rookie class with 14 goals and 26 points. ''We wanted to go out there and give it everything we had every night. I think we were able to do that.''
Nelson scored the lone shootout goal on the Islanders' second shot. He snapped a shot that rookie Connor Knapp got a piece of with his stick. But there was enough backspin for the puck to dribble in.
Anders Nilsson stopped 36 shots through overtime and all three he faced in the shootout. Nilsson clinched the victory by using his glove to sweep away a puck that got away from Ville Leino as he drove to the net.
Anders Lee, a recent call up, scored twice in a game the Islanders never led until the final score.
The Sabres bookended their season with long droughts. Buffalo got off to a 2-13-1 start, and ended with a 2-16-2 skid.
''This is our job and we failed. So it's definitely salt in the wound,'' forward Marcus Foligno said. ''I guess when it rains it pours, and you really just got to keep putting your head down and moving forward.''
Though both teams' rosters were depleted by injuries, the Islanders' fill-ins proved to be better.
Down 2-0, Lee scored both his goals in a span of 3:40, bridging the second intermission, to tie it 17 seconds into the third period.
Mitchell put the Sabres ahead by deflecting in Rasmus Ristolainen's shot 10:09 into the third, before Nelson scored the equalizer.
Using Ristolainen as a screen, Nelson snapped in 40-foot shot over Knapp's left shoulder.
The only thing on the line for the Islanders was where they would finish in the overall standings. The win pushed them into 26th place, two points ahead of Calgary.
There is a Sabres' tie-in for the Islanders connected to a trade in which Buffalo sent Thomas Vanek to New York for Matt Moulson and a first-round draft pick in one of the next two drafts. The Islanders have until June 1 to determine whether to give up their selection this year or hold off.
NOTES: The Sabres' 21 wins are the fewest in an 80-plus-game season, and rank second fewest behind Buffalo's 16-43-19 finish in 1971-72. Buffalo matched the 21 wins it had in the lockout-shortened season last year. Their 51 regulation losses are the most ever. ... The Islanders went 21-18-2 on the road for their best finish since going 21-15-3-2 in 2001-02. ... The Sabres were forced to call up G Andrey Makarov, D Mark Pysyk and LW Nicolas Deslauriers from AHL Rochester after the team lost five players to injuries at Boston on Saturday.