PHILADELPHIA -- Each day before the Mets play, Buck Showalter checks in with every reliever on his roster. He talks to them to see how they have recovered from recent outings. He asks whether they can pitch that day. Then he makes his decisions -- taking the player’s feedback into account but not relying on it exclusively.

Before the Mets suffered one of their worst losses of the season on Sunday, a 7-6 defeat to the Phillies that pushed them a season-high 15 games out of first place, setup man Adam Ottavino told Showalter that he was available. He hadn’t felt perfect the night before in throwing 26 pitches to record two outs, but he was ready to go if needed. Showalter responded that he would only use Ottavino if the game went to extra innings.

Similarly, closer David Robertson had recorded five outs on Saturday but done so on an ultra-efficient 13 pitches. Showalter intended to use Robertson for a maximum of one inning. Left-hander Brooks Raley, who had pitched on consecutive days, was unavailable. The Mets have never used him three games in a row.

That was the scenario that brought rookie Josh Walker to the mound with a three-run lead in the bottom of the eighth. Walker did not retire any of the three batters he faced. Next out of the bullpen was Jeff Brigham, who had posted a 5.19 ERA in June. Brigham induced the ground ball he needed, but third baseman Brett Baty double-clutched and threw wildly to second base, where Jeff McNeil could not glove it.

As Ottavino sat in the bullpen feeling guilty about his idleness, Brigham issued a bases-loaded walk, then hit consecutive batters to force in the game-tying and go-ahead runs. He joined Óliver Pérez as the only Mets pitchers to hit two batters in a row with the bases loaded.

Only after all this unfolded did Robertson begin warming for an appearance that never occurred. By then it was too late; the Mets had lost for the 15th time in 20 games without playing the bottom of the ninth.

“What else could we do?” Showalter said of his reliever usage. “That was kind of where we were.”

The situation evoked comparisons to the 2016 American League Wild Card Game, when Showalter -- then Baltimore’s manager -- left Cy Young candidate Zack Britton in the bullpen as lesser relievers pitched and, ultimately, lost that game. Afterward, Showalter explained that he did not want to use Britton in a tie game because he would have had no one to close if his team took the lead. His logic for avoiding Robertson was identical.

The urgency of Sunday’s contest couldn’t match that of a win-or-go-home playoff, but for the Mets, it was still a rubber game against a division rival at a crucial juncture of their season. Over the past three weeks, the Mets have seen their chances of making the postseason dim considerably. A series win over the Phillies might have represented a turning point.

Instead, the Mets lost behind Carlos Carrasco, Dominic Leone, Grant Hartwig, Walker, Brigham and Vinny Nittoli. Combined, those pitchers hold a 5.25 ERA. Two of them were not in the organization at the start of May. Hartwig, to his credit, pitched two scoreless innings.

“They’re capable of doing the job,” said Showalter, who was ejected in the ninth inning for arguing balls and strikes. “They just didn’t do it today.”

In his postgame press conference, Showalter said multiple times that he didn’t understand the line of questioning surrounding his bullpen usage. He reiterated his desire to stay away from Raley or Ottavino, and to hold Robertson for a save situation in the ninth.

“I don’t get it,” Showalter said. “What am I missing?”

Part of the problem is that Mets starters such as Carrasco have not routinely pitched deep into games. Part of it is that with Edwin Díaz on the injured list and Drew Smith serving a suspension, only three of the five high-leverage relievers the Mets brought to Spring Training are active. Over the course of this season, general manager Billy Eppler has made a slew of waiver claims, free-agent signings and trades, but he has yet to import another top-tier arm.

Perhaps that will change before the Aug. 1 Trade Deadline. Perhaps not. Right now, the Mets run the risk of reaching that point with a poor enough record to make a buying spree imprudent.

“Hopefully,” Brigham said, “there’s light at the end of the tunnel.”

Showalter should, at least, have Robertson, Ottavino and Raley all available Monday when his team opens a three-game series against the Brewers. No guarantees exist that the Mets will hold a lead in that one, but if they do, their top bullpen arms will be well-rested.