Nate Schmidt sat at his stall inside the Washington Capitals’ practice facility earlier this week, basking in the reality of his current role on the team. Less than 30 games into his NHL career, the rookie defenseman often finds himself skating more than 20 minutes a night and is paired with John Carlson against the toughest matchups opponents have to offer. “If you would have told me this about a month ago, I don’t know that I would have believed you,” Schmidt said. The Capitals didn’t expect things to unfold this way, either, but 28 games into the season, here they are: relying on Schmidt and several other inexperienced defensemen like him, for better or worse. That means finding ways to overcome rookie mistakes on a nightly basis and leaning on established blue-liners not only to handle a significant workload but to help minimize the impact of any errors from their teammates. It can make for an overwhelming situation for the defense as a whole and lead to the type of inconsistency that has become part of Washington’s season thus far. “It makes it difficult, and I think that’s one of the reasons we fight to get out of our own end at times,” Coach Adam Oates said. “There’s always that ‘sophomore jinx’ term — guys have great first years, and what happens in the second year? The game is not that easy. There’s a drop-off sometimes. We’re kind of trying to watch that all of the time with the kids.” Top-level defensive depth was a deficiency for Washington heading into the season, one that was exacerbated when veterans John Erskine and Jack Hillen were both forced out of the lineup with injuries in October. While neither Erskine nor Hillen is likely a long-term solution to rounding out the top four, both offered familiarity and stability. With Erskine and Hillen sidelined, the Capitals’ lineup on any given night has featured two to three defensemen who have fewer than 70 games of NHL experience in Schmidt, Dmitry Orlov, Steve Oleksy and Alex Urbom. Schmidt has been the only one with long-term sticking power so far, showing he can handle increasing responsibility, but he’s still a relatively raw talent transitioning from the NCAA at Minnesota to playing three and four games a week in the NHL.