When the Nationals are on the road, particularly when they are struggling there, Bryce Harper always talks about the importance of playing in front of his home crowd. When asked about the atmosphere at Citi Field in August, Harper praised the Nationals Park crowd instead. But after Monday’s 8-5 loss to the Mets, in what is arguably the most important regular-season series in Nationals history, Harper chose unfiltered honesty when asked about the atmosphere at Nationals Park.

“I mean, they left in the seventh, so that’s pretty brutal,” Harper said. “I don’t know. Whatever.”

Harper was not wrong. The Nationals announced attendance at 34,210, which is above their season average, though the park was not full. By the eighth and ninth innings, after the Mets had turned a topsy-turvy game their way and opened a three-run lead, much of the upper deck and visible swaths of the lower levels were more sparsely populated than they once were.

When the Braves were in town, closer Jonathan Papelbon, who pitched in vaunted baseball towns Boston and Philadelphia, noted that Nationals fans weren’t standing during his two scoreless innings in a game Michael A. Taylor eventually ended with a walk-off home run.

“I’ve got a little bone to pick with some of the fans here tonight,” Papelbon said then. “I saw a few of them sitting down. I’m not gonna lie, we need to stand up in those situations. Let’s get that going, ya know what I mean. Because this is playoff baseball.”

Harper was asked whether Monday’s game felt like a playoff game.

“I mean, playoffs is totally different. When we play in the playoffs, our fans are going nuts. They’re going crazy. I think the loudest I’ve ever heard it was probably when me and (Asdrubal) Cabrera went back-to-back in (Game 1 of the 2014 NLDS). That was pretty insane. Throwing the towels, doing what they’re doing, that was pretty incredible. This is a totally different atmosphere than what playoffs is like.”