Karl Alzner has been a fixture on the Caps’ defense for years. (AP Photo/Nick Wass)

Throughout the year, Karl Alzner has light-heartedly reminisced with Jay Beagle about their first Capitals development camp a decade ago, when Alzner was still a teenager fresh from being drafted. Those chats have followed more serious ones about how this could be their last run together with Alzner’s contract expiring after this season.

He knows nothing will be resolved until Washington’s playoff run ends, but it’s been hard to avoid thoughts about the future. Understanding the salary cap constraints coming this summer when several young players will need new contracts, he has occasionally scanned the Capitals’ roster, trying to determine which players the team will want to keep at the cost of a raise and which will have to move on.

“I mean, I’m realistic and I know it’s pretty rare for someone to stay in one place their entire career,” Alzner said earlier this month. “So, I’m making the best of it because this is a heck of a team, on and off the ice. And yeah, we’re going to worry about trying to secure some more trophies hopefully.”

Considering this could be Alzner’s final year with the only pro team for whom he’s ever played, it’s been a rocky one in some ways for the defenseman. Offseason sports hernia surgery and a groin injury from the end of last season have continued to nag him, and now as the Capitals enter their second-round matchup with the Pittsburgh Penguins, an undisclosed upper-body injury that kept him out of the lineup for four games in the series against Toronto has left his status uncertain.

Alzner’s health is improving, and he skated with the team in a full practice for the first time Tuesday. But after defenseman Nate Schmidt impressed in Alzner’s place against the Maple Leafs, it’s unclear if Alzner will regain his spot in the lineup.

“I think so,” Alzner said when asked if he expects to play when healthy. “Yeah, I didn’t really think about that. I guess that’s a good point. But yeah, I’m not too sure. I hope so, I guess.”

Alzner is Washington’s Iron Man, playing in 599 consecutive games, including the playoffs, before this recent injury. As he recovered from a partially torn groin muscle before the season, he was in unfamiliar territory, reaching out to friends and former teammates around the league who had experienced something similar for guidance about how he would feel going forward.

He had seen how former teammate Brooks Laich never quite regained his form after a groin injury. But even that didn’t prepare him for what has amounted to a year-long recovery that can’t be helped by sitting out.

“It’s kind of been standing still at a certain percent,” Alzner said. “There are days when I’m stiffer than other days and I can’t quite move as good, and so I have to manage the game a little differently. … I’ve never been the fastest skater, but I’ve always been a good enough skater where I can a lot of times skate myself out of trouble or catch up, if need be, and this year, I’ve been a little bit slower.

“Part of it, I’m sure, is mental just because you want to guard it a little bit. Of all years, this would be a year where I wouldn’t want that to happen because the team is good and I want to be able to help as much as I can. But at the same time, it’s hard to get over that mental hurdle.”

That aspect has arguably affected Alzner’s play. Averaging 19:47 of ice time per night, he scored three goals and 10 assists, his worst offensive output in an 82-game season since 2010-11. As a shutdown defenseman, scoring is not the best way to measure his success, particularly with Alzner almost exclusively facing the other teams’ top forwards. Capitals coaches still trusted him that role because he had proved capable of the challenge over the course of his career.

“Probably he had a stronger season last year than this year,” Coach Barry Trotz said before the postseason.

“His ability over his career to always play in top situations against top players gives him an underestimated value of experience,” associate coach Todd Reirden said. “He’s battle-tested in very difficult situations and I think that’s something that is an advantage for our team. Having gone through a lot of difficult meaningful situations, whether it’s at the end of the game when the other team has the goalie pulled or the penalty-killing aspect for our team. …

“You don’t win 55 games in this league if you don’t have players who do that for you. We’ve won 111 games over the last two years, and he never missed one of them. He’s played in all of those situations; he’s had a huge role in helping us have that type of success as a team.”

But that success has not been illustrated by his individual statistics. Alzner was last among the Capitals’ regular blue-liners with just 47.2 percent of the shot attempts coming from Washington when he’s been on the ice. The coaching staff’s rationale in continuing to hand him the toughest defensive assignments was that if he could successfully get through his shifts — and he arguably did with a plus-23 rating this season — that would free the team’s other defense pairs to play against easier forwards and potentially generate more offense.

“I’ve said from Day 1 since I’ve been here that I’m not a statistical person,” Alzner said. “If you want to rate me on that, I’m a different player than if you rate me on other things.”

General Manager Brian MacLellan has acknowledged that with the roster containing 11 players entering either restricted or unrestricted free agency this summer, “the math just doesn’t add up” to re-sign everyone. For Alzner, the only one of the Capitals’ four unrestricted free agents who has spent his entire career with Washington, the feeling of unfinished business would be stronger if the Capitals fall short of their championship goals. He’s spent the past 10 years trying to be a part of that.

“It’s been a good year for me, but the way I’m going to sum up my year is by what happens now,” Alzner said. “That’s going to be the determining factor for me.”