Thursday night's 5-4 loss to the Washington Nationals snapped the St. Louis Cardinals' winning streak at a season-high eight games.

But the Cardinals' most impressive run of the year has put them in position to get into position. St. Louis can further improve its standing Friday night when it starts a three-game weekend series against the Milwaukee Brewers in a National League Central showdown at Busch Stadium.

The Cardinals (66-56) trail Milwaukee (68-55) and Philadelphia by 1 1/2 games in the wild-card race. St. Louis slipped five games behind NL Central leader Chicago, thanks to the Cubs' 1-0 win in Pittsburgh.

However, the fact that St. Louis has surged into contention after spending most of the season's first 3 1/2 months married to mediocrity has given its clubhouse a different vibe. Gone is the tense aura that enveloped the team in the days before manager Mike Matheny was canned July 14.

"We know the offense is going to show up at some point, whether it's the first, fifth or ninth," center fielder Harrison Bader said. "The pitchers are going to keep us in the game, so we're confident. We just came up a little short (Thursday)."

The prime reason was a bugaboo that has haunted the Cardinals for most of the last three years -- a lack of defense. They made three errors and handed the Nationals three unearned runs, digging a 5-1 hole that proved to be too deep from which to climb.

"You know there's a human element in this game," St. Louis interim manager Mike Shildt said. "A couple of guys who normally make those plays just didn't do it. It was completely uncharacteristic of this team lately. It was one of those nights."

To get off to a good start in a big series, the Cardinals have tabbed Jack Flaherty (6-6, 3.22 ERA) to make his third appearance of the year against the Brewers. That's because Flaherty has dominated the Brewers in the first two games, fanning 22 hitters in 12 innings.

That includes a 13-strikeout performance on June 22 at Miller Park, where Flaherty took a no-hitter into the seventh inning. Jesus Aguilar ended that by golfing a game-tying homer, then walked St. Louis off in the ninth with his second homer of the game.

Milwaukee counters with its own rookie right-hander in Freddy Peralta (5-3, 4.47). After dazzling in consecutive June starts, whiffing 17 in 13 scoreless innings against Pittsburgh and Kansas City, Peralta has been shakier lately.

His last start was his worst. Peralta took a savage beating on Aug. 10 in Atlanta, permitting seven hits and seven runs in three innings of a 10-1 loss. Peralta walked five and fanned three, giving him 15 walks in his last 19 innings.

"Today, I wasn't able to get ahead," Peralta told mlb.com after the loss to the Braves. "I was working behind in the count a lot, and they were just kind of sitting on pitches."

The Brewers might be short-handed for the series. Outfielder Ryan Braun (rib cage tightness) and catcher Manny Pina (left shoulder) left Wednesday's 8-4 loss at the Chicago Cubs early. Their status for Friday night wasn't known as of late Thursday evening.