The Islanders have spent the past week bolstering their own playoff hopes.

Now, they can deal a massive blow to another team’s chances of making the postseason.

Those are the stakes when the Capitals come into UBS Arena on Saturday with a first playoff miss since 2013-14 and second since 2007-08 seeming more likely by the day.

Washington, which rallied to beat the Islanders 4-3 in overtime when the teams met in mid-January, has since undergone a spiral and is clinging to its playoff life, the lowlight being a six-game losing streak through late February.

That has put the Capitals in perhaps the worst position out of the seven teams in the wild-card race, with 69 points in 66 games — one game in hand to the Islanders, who are on 76 points.

In other words, if the Islanders can make it a nine-point deficit with a win on Saturday, it would become pretty hard for the Capitals to catch them.

Off the back of three straight wins, including inspired third-period performances against the Sabres and Penguins, the Islanders are understandably confident.

“We’ll make sure that we refocus here,” coach Lane Lambert said following the 4-3 overtime win over Pittsburgh on Thursday. “We get our rest and make sure we’re ready to play Saturday. Obviously, every game is huge. The more wins you can get, the better it is.”

Lambert did not bite when asked if he felt something special brewing after the comeback victory, but make no mistake, the Islanders are a team feeling good about themselves right now.

“You’re gonna have a night maybe where you’re a little bit off,” he said. “The key to a good hockey team is to find a way to win a game like that and we did.”

The Islanders equaled a club record on Thursday in winning their fourth game this season when trailing by at least two goals at the second intermission.

That matches their total from the seven prior seasons combined.

Prior to Thursday, the last time the Islanders came back from a two-goal deficit with under 5:30 to play was Nov. 19, 2019, also against the Penguins and also with Brock Nelson scoring the overtime winner.

Martin Fehervary (lower body) and Nick Jensen (upper body) both participated fully in Washington’s practice on Friday and could play against the Islanders. John Carlson, who took a puck to the head in December, skated in a noncontact jersey, but won’t play Saturday.