The Mets went 2-for-13 with runners in scoring position and stranded 10 men on base, despite outhitting the Brewers, 12-8.
"I thought we should have scored enough runs to win that particular game," Mets manager Jerry Manuel said.
Just how many runs exactly?
"That's a good question," Manuel said.
And one the Mets' bats struggled all afternoon to answer.
"Obviously, we struggled with men on base, men in scoring position," Manuel said. "But I think the good thing is we are at least putting ourselves in those positions. And we have to continue to do that until we have a breakthrough."
Early on, a breakthrough looked plausible, as the Mets scored in the first inning courtesy of Carlos Delgado's two-out one-hopper to the fence. The double easily plated Daniel Murphy, who tied a career high with three hits.
But the Mets squandered their subsequent opportunities, hitting into three double plays, and were unable to capitalize on some defensive breaks.
"It's a little frustrating, "said Manuel, who added that he was encouraged by his team's constant offensive pressure. "Unfortunately right now, we aren't coming through."
Down 2-1, the Mets caught a break with two outs in the fifth inning when Corey Hart, battling the sun, let Jose Reyes' hit drop in front of him. The speedy Reyes made it all the way to third, but Murphy grounded out to end the frame.
The Mets threatened again in the sixth while trailing, 3-1. Beltran had a two-out single and Gary Sheffield hit a double off the left-field fence to put the tying run in scoring position. But Fernando Tatis hit a ball to the left-field warning track, narrowly missing a three-run homer, to end the inning.
Omir Santos opened the seventh with a triple off Milwaukee starter Jeff Suppan, who was subsequently replaced by Mitch Stetter. Stetter sent Ryan Church down swinging, but the Amazins pushed their second run across on Reyes' infield single. Murphy followed with his third hit and David Wright drew a walk from Mark DiFelice, loading the bases for Delgado.
But Delgado hit the ball right back to Todd Coffey -- the fourth pitcher of the inning -- for an easy 1-2-3 double play.
To their credit, the Mets -- who wrapped up a series victory following Saturday's win -- were disappointed, but denied being frustrated that they let Sunday's game slip away.
"We just didn't come up with the big hit when we needed it," Sheffield said. "And that's just something we have to correct."
"Of course [losing is frustrating]," Wright said. "The idea is to win. So when you don't, it's frustrating.
"They didn't get a lot of hits, but they got them at the right time."
No one was more aware of that then spot starter Nelson Figueroa.
Recalled from Triple-A Buffalo to start in place of Mike Pelfrey (right forearm tendinitis), Figueroa rebounded from a 29-pitch first inning to give the Mets six solid frames. The journeyman allowed five hits and three runs, including Mike Cameron's solo homer in the sixth, and was designated for assignment following Sunday's loss.
"He performed well enough for us to win the game," Manuel said. "It would have been a really big win for us, given the fact that we were using a spot starter."
And given the fact that the offense cranked out 12 hits -- five of which were for extra bases -- off Suppan.
"If we continue to put pressure and give ourselves RBI opportunities and hit with men in scoring position, we are going to come through," Wright said.
Manuel was equally confident that the Mets' offensive woes aren't related to last season, when the team went completely cold.
"We haven't clicked well, and we will," Manuel said. "We have too many good hitters not to."
There were some encouraging signs. Six different Mets had a hit, reserve catcher Santos was a career-best 2-for-4 and Murphy and Reyes both went 3-for-5.
"I can't say that at this point, this early in the season that I would be upset with anybody's approach with men in scoring position," Manuel said. "I think it's more due to anxiety. And they want to get it done in a bad way, and that's not all that bad."
Brittany Ghiroli is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.