WASHINGTON — It’s no secret Alex Ovechkin ain’t a young pup anymore. There are a lot of miles on the odometer as he enters the offseason ahead of his 20th NHL season.

But it was still shocking to see how little used he was Sunday night en route to the Washington Capitals being the first team eliminated this postseason.

In a must-win game, Ovechkin was dislodged from the top line, played on a seldomly deployed line at even strength with Sonny Milano and Hendrix Lapierre, and logged the sixth-lowest ice time (15:26) of his 151-game playoff career.

He finished a playoff series with zero points for the first time in his career and only had six shots.

Why was he almost forgotten in Game 4 during the biggest moments?

The 38-year-old was tired, coach Spencer Carbery alluded, after a torrid second-half pace in which he scored 23 goals and 36 points in the final 36 games to help the Caps make the playoffs on the final day of the regular season.

“He could speak to this, but I think that this year and leaning on him down the stretch the second half of the year, he did an incredible job of finding his game,” Carbery said after Sunday’s 4-2 season-ending loss. “And also not just his game, but we were so scoring-challenged all season long. So the second half of the year, we even become more (feeble offensively). We (trade) Anthony Mantha, (Evgeny Kuznetsov) is out. And then you’ve got (T.J. Oshie) out for a while. So you’ve got all these different factors, right, that make it even more of a challenge for you to produce offensively.

“So he comes in post-February … and so our season is hanging in the balance. … Point I’m getting at is, if he doesn’t go on that scoring run … we’re not even sitting up here, right? He was scoring consistently every single night. So what I’m getting at is that was a lot: the second half of the year and especially the last, call it, two weeks, where every game felt like life or death for our team. And again, he could answer that more accurately, but I feel like that took a lot out of him physically and mentally.”

Makes sense.

Ovechkin is 38, and adding in the fact he was playing the New York Rangers, who can check you all over the ice and gave up the fourth-fewest goals in the East this season and had the league’s third-best penalty kill, life was always going to be hard for him. Really, who else were the Rangers going to focus on?

Ovechkin had four shots in Game 3 and one each in Games 2 and 4. Other than one Grade-A chance that required an awesome lunging save from Igor Shesterkin on a Game 3 power play, he didn’t really appear dangerous.

He was denied the puck — or, as some former NHL coaches said before Game 3, wasn’t working hard enough to get it.

“The defense was awesome,” Shesterkin said. “All four games, they play in front of him and didn’t let him do anything.”

At even strength, Ovechkin was largely a non-factor. Where he could have made his mark was on the power play, but the Rangers did a great job fronting him and preventing him from providing much of any risk.

“The power play is such a big part of it, right?” Carbery said. “When that is struggling, and he’s not getting the opportunities, puck touches, shots — they checked him so tightly over there that now all of a sudden, every time he gets a puck, he’s got a half-second to make a play, and there’s usually a stick or some shin pads on him. So I think that played a major role in his individual play through the series.”

Carbery noted that the Rangers made life tough for Ovechkin in the first two games at Madison Square Garden, with the Vincent Trocheck line going largely up against the Ovechkin-Connor McMichael-Oshie line, along with defensemen Ryan Lindgren and Adam Fox. But things didn’t get easier in Washington, so much so that Carbery seemingly downgraded Ovechkin in Game 4 after an ineffective Game 3.

Ovechkin, looking weathered after Sunday’s game, admitted he didn’t play well.

“We just didn’t score,” he said. “Our line didn’t score lots of goals — and me. I didn’t play well, so it’s kind of sucks that we played bad.”

After a 31-goal season, Ovechkin is 42 goals from becoming the NHL’s all-time leading scorer — passing Wayne Gretzky’s record of 894. He hopes the Capitals can keep growing — that some of their up-and-comers continue to develop and contribute offensively. If that happens, some of the load will be removed from Ovechkin’s broad shoulders and perhaps he’ll have a couple more playoff runs in his future before his first-ballot Hall of Fame career ends.

“No one believed in this group, that we’re going to make the playoffs this year, but we stick together, we fight for it until the last game of the season and we get the opportunity to play in the playoffs,” Ovechkin said. “We still have young guys who played in Hershey last year and they take a huge step forward and they take that experience and next year those guys are going to be much better.

“I hope I’m still going to get a couple chances.”