When is the last time an NBA team’s superstars overachieved but the team underachieved?

In nearly every way, this Nets season has been unique.

After missing 21 games with a knee injury, Kevin Durant has reestablished himself as maybe the best player in the world. Kyrie Irving — who was banished from the Nets in October because he was (and is) unvaccinated, who did not play a game until January and whose season has been all starts and stops since — has shown no signs of rust and plenty of signs of all-time greatness.

In a star-driven league, typically the big names take their teams as far as they can. But the eighth-place Nets (38-34) have taken steps back as their superstars, when on the court, have been probably better than advertised.

It is not clear if the Nets ever will be whole this season, but their Big 1 ½ has been enormous.

Durant will not qualify for the scoring title — a player needs to appear in 58 games to be eligible — but his 29.6 points per game is his best since 2013-14 and would have been fourth in the NBA entering play Tuesday, behind just LeBron James, Joel Embiid and Giannis Antetokounmpo.

As defenses have keyed on him and begun blitzing multiple defenders, he has responded by trusting his teammates and posting a career-best 6.1 assists per game, including the clinching alley-oop to Nic Claxton on Monday.

“We needed” his 37 points, nine rebounds and eight assists in the Nets’ win over Utah, coach Steve Nash said, “and he was incredible.”

In the nine games — six of which were wins — since returning from his MCL sprain, Durant has rarely needed a breather. Entering Wednesday’s matchup in Memphis, he has averaged more than 30 points and shot 55.1 percent from the field and 92.4 percent from the free-throw line. There might not be a more locked-in player in the league aside from his own teammate.

What Irving is doing this season, Seth Curry said last week, is “something like we haven’t seen and won’t see again.”

Since his season debut on Jan. 5, Irving has played as many as five games in a row and missed as many as four straight. He will be back in the lineup against the Grizzlies, playing for the first time in eight days. Like his game, his season has been filled with hesitation — and like his game, he is finishing well.

Irving has averaged 44 points in his past three contests. He practices, he dominates, he disappears for a stretch, and he does it again.

“It’s very, very difficult,” said Curry, who himself has been in and out of the lineup with ankle issues. “Nobody would probably blame [him] if he went out there and was rusty.”

“For him to keep that rhythm going over the course of the time I think is the [most] impressive part,” Patty Mills added. “So how he goes about looking after his body and being professional in that sense, to come in and just slide right in there I think is credit to exactly who he is and what he does. It’s amazing to watch.”

Irving, a career 47.1 percent shooter from the field, has been hitting 49 percent of his shots. He is draining a career-best 43 percent from beyond the arc, which would be third best in the NBA if he qualified.

“He has fresh legs, which is a bonus,” Curry said, “but to keep the skills and the mentality and the game speed part of it is tough to do.”

Because he has not been vaccinated, Irving is eligible for just three of the Nets’ final 10 regular-season games, and any games played by Ben Simmons (herniated disc) would be a surprise. It is possible — and perhaps likely — the role players around the Nets will continue to be leaned on more than the team would want.

But Durant playing like the best player in the world and Irving — half the time, at least — looking like the most skilled on Earth gives them a chance in the postseason.

And if the Big 1 ½ isn’t enough, by all accounts the fans and media will be harder on Irving than anyone in the Nets’ locker room.

“We love Kyrie as a human being. I don’t think we were ever upset at him as much as people on the outside were,” Durant said Monday. “We get that it may affect the outcome of some basketball games, but that’s not the only reason why we love Kyrie as a person. … I think overall him as a human being, we respect who he is, [and] we respect the game on top of that.”