PHILADELPHIA — The day after they clinched the top NL wild-card berth, the Mets finished the regular season in a mostly irregular game.

With nothing to play for, the Mets got a few key players an at-bat or two and then let their reserves complete a 5-2 loss to the Phillies on Sunday at Citizens Bank Park.

The Mets, who will host the NL wild-card game against the Giants on Wednesday night at Citi Field, finished the regular season 87-75. Clinching with one day to go in the regular season allowed them to save Noah Syndergaard for Wednesday’s game against San Francisco ace Madison Bumgarner.

“The most important thing was getting in first,” manager Terry Collins said. “I thought it was huge to win [Saturday]. We’ll have fresh pitching and fresh players, which will make a huge difference.”

Collins gave his regulars the option to take the day off. Curtis Granderson, Asdrubal Cabrera and Jay Bruce decided to play and were the top three in the order. The other regulars sat.

“Some of the guys want at-bats,” Collins said. “They don’t want to sit for three days without getting some at-bats. Grandy wanted to hit, Cabby wanted to get a couple at-bats. Jay wanted a couple at-bats. We’ll get ’em in and get ’em out.”

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Granderson had two plate appearances and went 0-for-1 with a walk. Cabrera flied out to center in his only at-bat before Matt Reynolds hit for him in the fourth. Bruce went 1-for-2 and was replaced by Alejandro De Aza in the bottom of the fourth.

It’s unclear who will start at first base for the Mets against the lefthanded Bumgarner. Lucas Duda started Sunday, went 0-for-4 and made two errors in the Phillies’ three-run seventh. James Loney popped out as a pinch hitter in the sixth. Righthanded-hitting Eric Campbell started at third and went 0-for-4.

Gabriel Ynoa started in place of Syndergaard and allowed one run and five hits in 4 2⁄3 innings.

The Mets didn’t get their first hit off Jerad Eickhoff until Bruce singled with one out in the fourth.

De Aza and Kevin Plawecki had RBIs for the Mets, who took a 2-1 lead in the top of the seventh. But the Phillies scored three times, helped by a double-error by Duda, who booted a grounder and then threw wildly to first as the tying run scored. Cesar Hernandez drove in the go-ahead run with a single off Erik Goeddel (2-2).