Manager Jim Riggleman watches another game drift away from his Nationals in the eighth inning, during which the Brewers scored five times. (Morry Gash/AP)

The theme of this Washington Nationals season has mostly been a slumbering offense, but that is being overtaken by redundancy. They play good defense. They often, but not always, pitch pretty well. They score precious few runs. And, lately, they usually lose.

The Nationals continued their worst stretch of this season with one of their worst losses, an 11-3 thrashing at the hands of the Milwaukee Brewers at Miller Park that, if not for the two runs the Nationals scored in the ninth inning, would have been their most lopsided of the year. The Brewers effectively sewed up their victory over the Nationals with their three-run, first-inning outburst, which included the first of Corey Hart’s three home runs and seven RBI.

The Nationals have lost five of their last six games, spiraling to a season-worst five games below .500 at 21-26, 1½ games behind the fourth-place New York Mets. In those five losses — which, it must be noted, have been wrapped around Friday’s remarkable 17-5 win — the Nationals have scored seven runs.

“We’re better than this, and we know it,” first baseman Michael Morse said. “It’s tough. The talent we’ve got, it’s frustrating right now. All it takes is a couple good innings, and we’ll get out of this. When things aren’t going your way, you start looking at everything. We’ve just got to play ourselves out of this.”

Brewers starter Yovani Gallardo became the latest starter to shut down the Nationals, retiring 15 straight after Morse smacked a colossal home run in his first at-bat while starting at first base following Adam LaRoche’s trip to the disabled list. Three games after the Nationals’ unprecedented offensive outburst this weekend, that seems more like a blip than the start of something. The Nationals remain punchless at the plate.

“You go through these things,” Manager Jim Riggleman said. “There’s no team that goes through a season without hitting some periods like this. You like to never concede to that, but I would say no team ever goes through a season without going through some bad times. The key is to get out of those bad times as quickly as possible.”

These days, when a Nationals starter builds an instant deficit these days, it makes the ultimate result predictable. Tom Gorzelanny led off by drilling Rickie Weeks with a slider that broke too far inside. Hart, the second batter of the game, followed by crushing Gorzelanny’s 1-0 change-up high over the fence in center, his first home run of the season, and the first of three he would hit Monday night. Before the beer vendor’s first trays had turned warm, the Nationals trailed, 2-0.

Two batters later, Prince Fielder made things worse. Fielder roped a 2-2 fastball with such force that it sailed not all that far above Gorzelanny’s head and still managed to nearly knock over the batter’s eye in center field.

After Fielder’s blast, Gorzelanny calmed, retiring eight of the next nine batters he faced and striking out six of the next 13. But his stable stretch ended in the fifth, when Hart smoked another two-run homer and Jonathan Lucroy added an RBI single.

Gorzelanny’s night was finished after five innings, with him having allowed six runs on eight hits — three of those home runs — a walk and a hit batsman. The Nationals have lost Gorzelanny’s last three starts, a span during which Gorzelanny has allowed 24 hits and six homers in 15 1/3 innings.

“It feels like all year, every mistake goes over the fence,” Gorzelanny said. “Bad things happen when you make mistakes.”

Then again, on so many nights for the Nationals, it hardly matters how many runs their starter allows. Monday, their latest outage didn’t happen for lack of opportunities. Morse detonated an opposite-field home run to the second deck in right field in his first at-bat. They did not score again until the ninth, which they entered trailing 11-1.

Even with Gallardo’s dominance, the Nationals mustered threats in several innings. They only managed eight hits and one walk, but they stranded nine base runners and went 0 for 10 with runners in scoring position.

In four innings, they left a man in scoring position, and not without some hard luck. Twice, with two on and two outs, Wilson Ramos rocked a fly ball that died on the warning track. (“I definitely thought his second one was going to go,” Morse said.) Two possible three-run homers became a new inning and another zero on the scoreboard.

“I don’t think anybody comes in here thinking, ‘We’ve lost the last few games, we really need to do something extra special to get things turned around,’ ” said second baseman Danny Espinosa, who will play Tuesday after leaving the game following a hit by pitch. “I think we’re a better than we’ve shown all year. We’re a real good team.”

Two relief appearances added intrigue to a game that, from a competitive standpoint, offered little. In the sixth, Henry Rodriguez pitched a 1-2-3 inning, giving him five straight scoreless innings and a 0.91 ERA on the season. He struck out Weeks in an at-bat that included two 100-mph fastballs, a 101-mph heater and an 84-mph inside curveball that froze him for strike three.

In the eighth, Riggleman called on Drew Storen in order to get him his first work since May 16. Storen jogged in with a 21-inning scoreless stretch, the longest active streak in the majors. Consecutive doubles erased that.

The unsightly end, for the Nationals, served as an apt bookend to the nasty beginning. In between, they had managed just three runs. The night included many oddities, but the most persistent thing remained the most troubling, or at least the most necessary to change.

“It’s not always going to be like that,” Espinosa said. “It’s going to turn our way. Those pitches on the corners, they’ll start going our way. We’ll get things rolling, and we’ll be fine.”