The Islanders’ win over the Rangers Thursday night came at a steep price. The Islanders confirmed on their Twitter account Friday morning that Anders Lee is out indefinitely after suffering a broken left fibula in the first period of the Isles’ 4-1 win, the result of being struck by a slap shot from teammate Johnny Boychuk. Tests on Friday will determine whether Lee will need surgery, but his season is most certainly over regardless of how far the Islanders go in the postseason.

Lee had 15 goals and 21 assists in 80 games, a drop-off from his 25-goal rookie season a year ago. But the big winger had been coming on strong the past two months, scoring eight goals in his last 28 games, including three game-winners, almost all from his usual spot in front of the opposing goal.

That’s where he was Thursday night when he couldn’t avoid one of Boychuk’s big shots. Lee tried to play two more shifts but obviously could not continue and the fracture was diagnosed before the team left Madison Square Garden with its third straight win.

The Isles are still without Travis Hamonic (knee), who skated lightly and without equipment Thursday, and Jaroslav Halak (groin), who skated with equipment but did not take any shots Thursday. Mikhail Grabovski has been feeling concussion symptoms for several weeks and has not done any hockey activities of late. None of those regulars are likely to be ready for the start of the playoffs.

There are also a host of more minor injuries to Islanders regulars. Matt Martin, Cal Clutterbuck, Brian Strait and J-F Berube were all out Thursday night, though Calvin de Haan returned after missing a game with a lower-body injury.

The Islanders still don’t know their first-round opponent. If they pick up three or more points in their final two games at Barclays Center, Saturday against the Sabres and Sunday against the Flyers, then the Isles will face the Penguins in the opening round. If the Isles get no points or any amount less than the Rangers, then the Isles face the Panthers next week.