Only four weeks ago, in a home win against the Philadelphia 76ers, the Luka Doncic-Kyrie Irving partnership looked nearly invincible, poised to become one of the NBA’s most menacing duos, prepared to lead Dallas to a comfortable playoff seed and perhaps even a feisty postseason run that set up the future. Just four weeks ago, those two combined for 82 points and this team was brimming with optimism.

Four weeks later, hardly any remains.

Dallas lost 116-108 to the same Philadelphia 76ers on Wednesday, a defeat that sunk the Mavericks to a 37-40 record that leaves them a full game out of the Western Conference Play-In Tournament with only five more to play. The Mavericks held a double-digit lead for several moments throughout the game’s first three quarters only to lose for the 13th time this season in a game in which they had built such a lead. Doncic and Irving had 24 and 23 points, respectively, far from their 42- and 40-point showings around this time one month ago.

But Doncic and Irving weren’t the problems Wednesday. Those continued to be ones that have existed all season, ones that start with roster construction and defensive talent deficiencies. More specifically, the Mavericks lost to the 76ers because Reggie Bullock and Maxi Kleber combined to shoot 2 of 12 from behind the arc, and because Josh Green continued to struggle finding his role and confidence on the court. Both Doncic and Irving forced Philadelphia into double-teams that opened up teammates, but the team’s 18-of-46 shooting on 3s, a respectable 39.1 percent, wasn’t enough to keep Dallas ahead in the fourth quarter.

“When you talk about playing advantage basketball, if they’re going to blitz (them) and put two on the ball, it gives us an advantage,” Mavs coach Jason Kidd said in his pregame media session, a predictive line about what eventually happened in this game. “Your role players have to take advantage of that.”

Doncic and Irving are beginning to show further signs of their developing chemistry, something that had been halted and hesitant due to injury absences by both in the past few weeks. And there’s only so much chemistry that ever needed to be built between two of the league’s most potent scorers, two basketball savants who are no easier stopped with man defenses than they are with prayers or the divine. With both players on the court, the Mavericks are still scoring 121.4 points per 100 possessions, per Cleaning the Glass, which would make them the league’s best offense if only those minutes counted.