NEW YORK -- Without the outstanding performances from goaltenders Thomas Greiss and Jean-Francois Berube down the stretch of the regular season, the New York Islanders would not have reached the playoffs, much less the second round.

On March 8, the Islanders were hosting the Pittsburgh Penguins, and with 4:22 remaining in a 2-1 regulation win, goalie Jaroslav Halak suffered a groin injury and left the game. Immediately after that game, Islanders coach Jack Capuano said the team had confidence in both Greiss and Berube and would need their best efforts in order to earn a postseason berth.

Greiss went 5-5-1 during his last 11 regular-season games, while Berube posted a 2-1-1 mark. It was a smart move by Capuano to publicly defend the team's backup goalies after Halak suffered the injury.

"It's important," Capuano said after practice Monday as the Isles prepare to host the Tampa Bay Lightning in Game 3 of an Eastern Conference second-round series on Tuesday, 7 p.m. ET, at Barclays Center. "They are the last line of defense back there and there's a lot of eyes on them when the red light goes on. I've had confidence in them because I'm in constant communication with our goalie coaches and see [Greiss' and Berube's] work ethic. And they perform, both guys. Berube's played well for us, and [Christopher] Gibson played well for us when he was in there. And we obviously know what Greiss can do. As you need secondary scoring, you're going to need goaltenders when a guy goes down that you can count on.

"They were the backbone of our team for the last month of the season. They've done a great job for us."

Greiss set career highs in games played (41) and wins (23) and finished the regular season with a .925 save percentage. In his first-ever postseason start on April 14 against the Florida Panthers, he made 42 saves. He posted a career-high 47 saves in a 2-1 double-overtime victory in Game 5 against the Panthers.

Thomas Greiss, left, and the Islanders were outshot 36-22 in their Game 1 victory over Tampa Bay. They were again outshot by the Lightning 31-20 in a 4-1, Game 2 loss. Scott Audette/NHLI/Getty Images

In the second round, he was outstanding in Game 1 and led the Islanders to a 5-3 victory with a 33-save performance. In Game 2, he was solid again, but the Lightning pulled out a 4-1 win to even this series.

Greiss, 30, has 130 games of NHL experience, but before this postseason, he had played only one playoff game -- for the San Jose Sharks during the 2009-10 season. Because he's older, he doesn't get rattled by much given his past experience. He was the backup to Evgeni Nabokov during the Sharks' run to the Western Conference finals in 2010.

"I've been on a bunch of teams that have gone deep, so it helps," Greiss said. "You have been there before and you know if you lose one game, or one day doesn't go your way, there's always the next day. You've seen lots of things, so you can just go back to that and control your emotions. It makes it a little easier because not everything is new for you."

Because he's played well and is one of the reasons the Islanders are in the second round, the job is Greiss' to lose. Meanwhile, Halak has practiced with the team twice in the last few days, but there's no timetable for him to be cleared to return. He hasn't played in eight weeks, and he said it feels like the beginning of the season for him to play again while he's working his way back.

"When you're injured, you've got to work even harder than when you're healthy," Halak said. "I feel good. I've made big progress, but I'm just taking it day-by-day right now."

He described his injury as bad timing, and as difficult as it's been, Halak has been impressed with Greiss' performance.

"When you get injured, it's always hard to watch the guys from the press box or from home and you're not able to help," Halak said. "They did a good job, and now just trying to get back. Just take it day-by-day, that's all I can do, and hopefully I'll be back soon.

"I've said this many times -- that we need two goalies to play well during the season. It was bad timing for me to get injured, but I'm just trying to work my way back to the lineup and back on the bench, so we'll see how long it's going to take."

Greiss is always smiling, but he says very little with the media around. He was asked Monday why he decided to become a goaltender as a kid.

"I was too lazy to skate," he said with a laugh. "I just wanted to try it out when I was young and I liked it."

These days, the Islanders are glad he did.