CRANBERRY, Pa. -- After the Pittsburgh Penguins announced on April 5 that defenseman Kris Letang would need season-ending surgery to repair a herniated disk in his neck, Letang stood up during a news conference that day and stated his belief that they could repeat as Stanley Cup champions without him.

There probably weren't a lot of people outside the Penguins locker room who agreed with Letang back then. Yet, here they are preparing to face the Nashville Predators in Game 1 of the Stanley Cup Final on Monday (8 p.m. ET; NBC, CBC, TVA Sports).

Pittsburgh has gotten this far with a mostly unheralded collection of defensemen who have played better as a group than the sum of their parts. It hasn't always been pretty and they've needed a good amount of help from the Penguins talented forwards and goaltenders Matt Murray and Marc-Andre Fleury, but they've done the job well enough to justify Letang's faith in them.

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"We know no one's going to replace him," Penguins defenseman Brian Dumoulin said Saturday. "We know that and we've just got to continue to play well as a group and don't get outside of [your] comfort zone. Everyone just do what they do best."

Letang, 30, did it all for the Penguins during their run to the Stanley Cup last season. In fact, a case could have been made for him to win the Conn Smythe Trophy instead of Sidney Crosby, even before he scored what proved to be the Cup-winning goal in a 3-1 victory in Game 6 of the Final against the San Jose Sharks.

Penguins coach Mike Sullivan relied heavily on Letang, playing him in all situations. His 28:52 in average ice time in the 2016 Stanley Cup Playoffs was nearly seven minutes per game more than the next highest Penguins player, defenseman Trevor Daley (22:08).

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He finished second among defensemen with 15 points (three goals, 12 assists), trailing only Brent Burns of the Sharks (24 points). Before his neck injury during a Feb. 21 game against the Carolina Hurricanes, Letang was leading the Penguins in ice time (25:31 per game). He had 34 points (five goals, 29 assists) in 41 games.

The Penguins initially hoped that with rest and rehab, Letang would be back in time of the playoffs. But it was eventually determined that surgery was unavoidable. Instead of viewing it as a blow to their repeat hopes, the Penguins other defensemen approached it as a challenge to prove that they could win without Letang.

"We're a confident group that way," defenseman Olli Maatta said. "We know we're good enough to win. … I think we're all a little different, everybody, but we all just want to play a simple game."

Instead of giving all of Letang's minutes to one defenseman, the Penguins have spread them out. Dumoulin leads the group in playing 21:55 per game, followed by Ron Hainsey (21:12), Maatta (21:02), Justin Schultz (20:12), Daley (19:39) and Ian Cole (19:09). Daley (lower body) and Schultz (upper body) have also missed time with injuries, so Mark Streit and Chad Ruhwedel have stepped in when needed.

For the most part, the defense-by-committee approach has worked well.

"If you look at last year in the playoffs, it was kind of Kris Letang and the rest of us," Dumoulin said. "I don't think that's the case right now. Whatever role that you're asked to do, whatever opportunity is there, I'm not going to be the offensive guy Kris Letang was or I don't think anyone in our lineup is going to be to that aspect. For me, it's go out there and take it as the next-shift approach and go out there and try to play my best. Not look ahead, not try to do too much. Just go out there and try to play like I have."

When healthy enough to play, Schultz has picked up the slack offensively with Letang out with 10 points (three goals, seven assists) in 15 games and taken his spot as the quarterback on the No. 1 power-play unit. With Schultz, Daley and Streit all getting time in that role, the Penguins power play has actually been better in the playoffs (25 percent) than during the regular season (23.1 percent).

After missing four games because of his injury, Schultz returned to score a power-play goal and also assisted on Chris Kunitz's winning goal in the Penguins' 3-2 victory in double overtime against the Ottawa Senators in Game 7 of the Eastern Conference Final on Thursday.

"We have a group back there that care about each other, that really play within their limitations," said assistant Jacques Martin, who runs the Penguins defense. "I think that's the key. And they've been able to raise their level of play."

No team has won the Stanley Cup without at least one top-tier defenseman since the Carolina Hurricanes in 2006, a defense that included Aaron Ward, Bret Hedican, Frantisek Kaberle, Niclas Wallin, Mike Commodore and Glen Wesley. Penguins general manager Jim Rutherford was the GM of that team, and Predators coach Peter Laviolette was its coach.

With Roman Josi, P.K. Subban, Mattias Ekholm and Ryan Ellis, the Predators have four impressive defensemen who'd qualify as a No. 1 on some teams.

"That's fine with us," Dumoulin said. "Obviously, they're great players, but there's no chip [on] our shoulders. We don't really pay attention too much. We try to stay level headed as much as we can. We know what we are as a 'D' corps. There's definitely a lot of talk, but we just take the same approach that we have been and go from there."