The Blackhawks are under plenty of scrutiny, but Nolan Allan isn’t.

That’s an accomplishment because Allan is, after all, a 21-year-old rookie defenseman. Most guys that young at that position are inherently inconsistent and a likely bet to have at least a few heart-stopping, chaotic shifts per game, as the Hawks experienced with Kevin Korchinski last season.

Allan, however, couldn’t be further from that. He looks more like a grizzled 10-year NHL veteran, which puts him on a promising track to become precisely that 10 years from now.

“He knows the type of player he wants to be going forward, which is great because not a lot of [players do],” said Hawks assistant coach Kevin Dean, who oversees the defense.

“He understands that if he wants to become the player I think he can be — [a player] that plays 10 or 15 years in this league — he’s going to be a stay-at-home defenseman who moves pucks well and blocks shots and is physical and hard around the net.”

Actual veteran defenseman Connor Murphy, whose 12-year career arc provides an ideal model for Allan to follow, has reached the same conclusion.

“Usually you notice with young defensemen — like me early in my career — [that] you have a couple of good games, but then the adrenaline wears off, and you get overwhelmed in some games,” Murphy said.

“He hasn’t shown that. He looks like a veteran because he’s steady and consistent in his work ethic and knows what he is as a player. He doesn’t try to over-complicate things or do too much. It doesn’t feel like you need to correct him much.”

Allan quickly has evolved from a training-camp surprise to a one-of-the-guys staple on the Hawks’ back end. The injuries to Alec Martinez and Seth Jones have kept a lineup spot open for him, and he hasn’t squandered the opportunity, averaging just over 13 minutes of ice time while appearing in 16 of 19 games. He played a career-high 18:04 in the Hawks’ win Thursday over the Panthers.

“I wouldn’t say [I felt] immediately comfortable,” Allan said recently. “I’m getting more comfortable every time I’m in the lineup. Obviously, [the game is] a lot faster than the AHL, but that’s something I’ve done my whole career: Just try to play steady. It’s nothing new to try to play that way.”

He admitted there are “still things each game that you’re surprised by,” such as the enduring strength of 33-year-old Stars forward Matt Duchene, whom he has faced a couple of times already. Things like that are reminders of how fresh and inexperienced Allan actually is, but those reminders are rare.

Dean has been particularly impressed by Allan’s physicality and defensive positioning, two longtime strengths. In Rockford last season, his ability to move the puck smoothly and turnover-free out of the defensive zone was considered a weakness, but he has improved substantially with that, too.

“Sometimes he gets the puck, and . . . he’s almost too relaxed,” Dean said. “Because he makes the right play 95% of the time. I do want to see him get the puck and move a couple of strides because I believe anytime a defenseman is skating, he’s going to have more options. And he’s good enough to see those options.”

In the years ahead, a horde of more heralded prospects will come for Allan’s job: Korchinski, Artyom Levshunov, Sam Rinzel and even Ethan Del Mastro, Allan’s AHL partner last season who seemed slightly above him in the prospect hierarchy at the time.

But results matter most, and reliable third-pairing stalwarts are valuable. If Allan keeps playing like this, he’ll deserve a cemented spot in the Hawks’ future depth chart.

“He’s very comfortable playing [this way],” Dean said. “And he wants to play that way, which is a credit to him and his maturity.”