NEW YORK — The frustration was evident early. And it was hard to tell what was bothering the Lakers more on Monday — was it the missed shots or the perceived missed calls?

If it wasn’t one thing, it was the other, the Lakers losing 111-108 to the lottery pick-bound Brooklyn Nets with tougher days over the next four weeks ahead.

Playing without four of their regular rotation players because of injury, the Lakers weren’t anywhere close to their best, physically shorthanded and mentally disengaged.

Austin Reaves, who needed to take on a more prominent offensive role with LeBron James out because of a groin strain, never got it going. Alex Len and Trey Jemison III, the bigs the Lakers have access to with Jaxson Hayes dealing with swelling in his knee from a bone bruise, combined for only two points and five rebounds.

And Luka Doncic, the engine the Lakers will need to push them through this brutal stretch of schedule, missed shots and looked toward the refs for whistles that never came. When he finally got his first one — midway through the third quarter, he threw up his hands in celebration. When a later foul was ruled on the floor, wiping out a made basket, he dismissively waved his hands at the refs in disbelief.

And needing a stop deep in the fourth, the Lakers forced a D’Angelo Russell miss, but the possession ended with Jarred Vanderbilt pushed to the floor and Zaire Williams scoring off the rebound.

Doncic needed 26 shots for his 22 points to go with 12 rebounds and 12 assists. Reaves missed 11 of 14 shots to go with his eight rebounds and 10 assists. Gabe Vincent and Dalton Knecht, filling in with the starters, scored 24 and 19 points respectively, and Jordan Goodwin had 17 off the bench, but the Lakers were never good enough executing on either end.

Brooklyn shot five more threes and 11 more free throws, the Lakers (40-23) attempting only two in the first half.

Monday’s game in Brooklyn was one of the few games the Lakers have this month against a team out of the playoff picture. They finish their current trip against Milwaukee and Denver on back-to-back nights before coming back to Los Angeles for five games in seven nights.

Before the game, JJ Redick said James’ injury was still being evaluated, and that the team doesn’t have a clear sense of the severity. Hayes’ knee injury is still considered day to day. Rui Hachimura, who is working toward a return from his knee injury, isn’t set for a re-evaluation until the Lakers return to L.A. And Dorian Finney-Smith wasn’t available because of continuing issues with his left ankle.

It meant the Lakers started Len at center alongside Knecht, Vincent, Reaves and Doncic — hardly a group with real on-court chemistry.

The Lakers turned the ball over 15 times, leading to 19 Brooklyn points. They stayed in the game because of Vincent and Goodwin, who made 11 of the Lakers’ 19 threes.