There is no more disappointing team in the NBA than the Phoenix Suns.

Being five games below .500 with 23 contests left in the season is sad enough. But sitting 3 1/2 games behind the final Western Conference play-in berth is borderline embarrassing.

The Suns are just one game ahead of the Portland Trail Blazers. Nobody outside the Trail Blazers’ offices considered Portland a possible playoff team.

When you start off with Kevin Durant and Devin Booker, you should be well above .500 and in zero danger of watching the postseason on television.

But after 10 losses over the past 12 games, let’s say the quiet part out loud: Phoenix is awful.

The Suns continued their underachieving ways Thursday night when they lost 124-116 to the visiting New Orleans Pelicans.

The Pelicans have been out of the playoff chase since December and have nothing to play for. They outplayed and outhustled the Suns all game long.

Zion Williamson recorded the first triple-double of his career. It is like he watched film of the shaky Phoenix defense and knew he’d be able to do anything he wanted. And he did, making 13 of 17 shots while compiling 27 points, 11 assists and 10 rebounds.

Oh, look here, the Pelicans visit the Suns again Friday. Note to Phoenix: Big Zion will probably be rested on the back-to-back.

The fewest points the Suns have allowed during their 12-game rut is 117. Phoenix is the squad you fatten up your average against because you know there will be defensive breakdowns and guys will be wide open for 3-pointers.

The Suns continue to talk a big game as if they are going to magically turn around their fortunes. Yet their playoff hopes keep declining.

After Thursday’s loss to the Pelicans, Booker defined what he sees as the problem with the Suns.

“Skipping over the details and always taking the ‘get ’em next game’ mentality,” Booker said. “At some point, you got to draw a line and (it) should’ve been drawn a long time ago.”

So, Book, let’s draw a line.

The line is directly below the Sacramento Kings, the 10th-place team in the West.

Guess what team is deservedly below the line? Oh yeah, the underachieving Phoenix Suns.

We’re not trying to pick on Booker, as he always plays hard and put together 36 points, nine assists and seven rebounds Thursday.

But it just makes zero sense that a team with Booker and Durant on it can’t play significantly better basketball.

That trade for Bradley Beal was a killer, and he’s not a good fit with the Suns. Tyus Jones is a good complement to Booker and Durant, while Bol Bol is promising and might still develop.

But most of the other rotation players are just guys: Nick Richards, Grayson Allen, Royce O’Neale, Mason Plumlee, Ryan Dunn.

Also, let’s not forget that Phoenix management fired Frank Vogel after one season as coach.

The Suns went 49-33 in the regular season under Vogel. Uh-oh, this year’s squad needs to go 22-1 the rest of the way to match that mark.

Vogel’s biggest miscue was getting swept by the Minnesota Timberwolves in the first round of the playoffs. Phoenix lost by an average of 15 points.

New coach Mike Budenholzer was supposed to be the answer. He has an NBA title and five 50-win seasons on his résumé.

That’s great stuff, but it’s starting to look like having Giannis Antetokounmpo on your roster is better than having Booker and Durant. How are the Suns getting worse as the season goes on instead of adjusting to the new coach?

Maybe Budenholzer isn’t comfortable holding Durant accountable. Durant is an all-time great, but he kind of marches to his own drum at this point in his career.

In fact, Durant had the next-game mentality that Booker isn’t fond of when pressed about the team’s struggles.

“Guys still want to figure this thing out. I’m confident that our group will come out (Friday) with a sense of urgency and be better,” Durant said.

It’s time for the Suns to draw another line.

Because right now, “most underachieving team” is stenciled on that line.