The loss was the Devils' fourth in five games and it spoiled an outstanding effort by Weekes in place of the injured Brodeur.
A four-time Vezina Trophy winner, Brodeur suffered a bruised elbow on Saturday.
Devils president and general manager Lou Lamoriello said before the game the team was awaiting test results. He gave no indication how long the 15-year veteran would be sidelined.
Brodeur's absence Monday marked the first time in 57 games dating to last season that he did not start. It also marked only the 21st time in his career that he did not dress for a game.
With Brodeur out of the lineup, the Devils basically didn't show up for the first period. They were called for five penalties and were outshot 20-3.
Only Weekes kept them in the game, and he nearly escaped the period without a goal.
Pominville got his fourth goal of the season with 34 seconds left in the period, just seconds after a 5-on-3 power play ended.
Spacek set up the goal with a pass from the right side to Pominville in the left circle. He found the top of the net as Weekes came across low to stop a shot along the ice.
Earlier in the period, Weekes had stopped Pominville twice in close, Thomas Vanek in close on a power-play shot and Tim Connolly after a great rush up ice.
Miller, who stopped 29 shots in shutting out Washington on Saturday, was at his best in the second period when the Devils had three power plays. He stopped three good point shots by rookie Anssi Salmela, two by fellow defenseman Johnny Oduya and a chance straight on by Zach Parise, who also had a good opportunity on a wraparound in the third period.
Until the Devils got the power plays, fans booed and had derisive cheers for shots on goal.
Kaleta stretched the lead 2-0 just under eight minutes into the final period. Standing about halfway between the goal and the blue line, he redirected a point shot Andrej Sekera between Weekes' pads.
Notes: Sabres D Craig Rivet returned to the lineup after missing five games with a knee injury. ...Devils D Paul Martin was out with an upper body injury. ... New Jersey recalled G Scott Clemmensen and Salmela from Lowell (AHL) with Brodeur and Martin out. ...
Giants Antonio Pierce and Plaxico Burress, and Phoenix Suns center Shaquille O'Neal were at the game.
