AP photo New York Islanders goaltender Ilya Sorokin (30) celebrates with Josh Bailey, left, and Cal Clutterbuck after Bailey’s winning overtime goal in Game 5 of an NHL hockey Stanley Cup first-round playoff series against the Pittsburgh Penguins in Pittsburgh, Monday.

For all the talk about how much playoff experience goes into winning the Stanley Cup and the guys with gray in their beards who have been there before, rookies are stealing the show early in this NHL postseason.

Three rookie goaltenders have won a game, the defending Stanley Cup champions are getting major production from a rookie forward and the likely rookie of the year has found his groove after a rocky start.

From New York Islanders goaltender Ilya Sorokin, Carolina’s Alex Nedeljkovic and Florida’s Spencer Knight making saves to Tampa Bay’s Ross Colton and Minnesota’s Kirill Kaprizov scoring goals, the first round is proving to be something of a rookie showcase.

“I think it’s a little bit in your mental makeup,” Lightning coach Jon Cooper said. “I’ve seen guys that are 28, 29 not be able to make some plays that 20- and 21-year-olds have been able to make, and it’s just having that mental makeup of calming everything down.”

Sixteen of the 27 rookie skaters who have appeared in the playoffs have at least one point, but the calm confidence is coming from the rookie goaltenders who have been playing like veterans.

Knight at 20 became the youngest goalie to start an elimination game and allowed a goal on the first shot he faced in his NHL playoff debut Monday night. Then he stopped the next 36 to keep the Panthers alive against the Lightning.

Knight left little doubt he will start again for Florida in another elimination game Wednesday night at Tampa Bay. The same goes for Nedeljkovic in net for the Hurricanes, despite the 25-year-old starting just 23 games during the season as part of a three-goalie tandem with Petr Mrazek and James Reimer.

Stopping 142 of 153 Nashville shots for a 2.13 goals-against average and .928 save percentage through four games was more than enough for Nedeljkovic to stay in net.

Islanders coach Barry Trotz wouldn’t think of taking Sorokin out after he stopped 48 of 50 Pittsburgh shots in a double overtime victory in Game 5, though veteran Semyon Varlamov carried the team at times during the regular season.

Trotz isn’t ready to crown Sorokin yet, despite a 1.66 GAA and .951 save percentage.

Kaprizov, the likely Calder Trophy winner as rookie of the year, had a rough start to the playoffs. The young Russian winger had just one assist to show for Minnesota’s first four games against Vegas before scoring a big goal Monday to help the Wild stave off elimination.

The polar opposite to Kaprizov’s hype, Colton has played an outsized role for the Lightning compared to expectations. He stepped in during the season amid injuries and put up 12 points in 30 games, so his two playoff goals haven’t been a surprise.

Confidence is oozing from Panthers rookie forwards Owen Tippett and Mason Marchment, who have combined for six points. Florida would be out of the playoffs if not for the duo and Knight.