NEW YORK -- The clock is ticking down on the Mets’ window of contention. As general manager Brodie Van Wagenen put the finishing touches on a trio of trades minutes prior to Monday’s Trade Deadline, those Mets already in-house were making the final outs in a 5-3 loss to the Marlins at Citi Field.

The new additions -- Todd Frazier, Robinson Chirinos and Miguel Castro -- can help. But for a team that left the field in fourth place, a season-worst five games under .500, improvements will need to happen quickly.

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“Especially in a short season like this,” manager Luis Rojas said, “you can almost feel like time is running out on you.”

Things happen quickly in a 60-game season. Take Jacob deGrom, for example. Dominant in retiring his first eight batters on Monday, five via strikeout, deGrom began showing cracks during a two-out rally in the third. He put out that fire, but he couldn’t do the same in the sixth, after Garrett Cooper homered and Pete Alonso committed a fielding error. Lewin Díaz, Miguel Rojas and Jorge Alfaro all followed with RBI hits, turning a two-run New York lead into a two-run deficit.

The Mets had taken an early lead in the third inning on a Jeff McNeil RBI double and a Dominic Smith sacrifice fly, then added another run on a Robinson Canó homer in the sixth. But they could not complete the comeback.

“We’ve lost some tough games, today included,” deGrom said. “We’ve been in every game. Everybody comes in every day like it’s a new day, ready to play. This short season, pretty much everybody’s in it, so if we can put some wins together and get this thing rolling a little bit, we’ll be right where we need to be.”

deGrom’s point is a fair one. Even in fourth place, the Mets walked off the field Monday just two games out of a playoff spot. Their remaining schedule is not easy -- outside of four upcoming games against the Orioles, the Mets will exclusively face contenders the rest of the way, including the Yankees, Phillies, Blue Jays, Braves, Rays and Nationals. But the Mets consider themselves a playoff threat, as well.

To that end, rather than let the Trade Deadline pass quietly, the team completed three separate deals in the minutes leading up to it. Each one of them was built to help New York win now: Frazier offers bench depth for a club lacking right-handed thump; Chirinos is an established backup catcher with offensive upside; and Castro could be the missing bullpen piece the Mets so desperately need.

Within the walls of the Mets’ clubhouse, there’s little doubt that they will improve. The question is when, and how much, and will it be enough?

“We can’t necessarily think too big,” Alonso said. “We just have to be totally locked in on our purpose, on our mission, every single day, pitch to pitch, out to out. That will be it.”