PITTSBURGH -- Two weeks ago, the Pirates were flying high into Chicago, coming off of an excellent first-half finish while expecting bigger and better things in the second half.

On Thursday night, they boarded a flight to New York at the lowest point of their season. The Cardinals finished off their four-game sweep of the Pirates at PNC Park, blasting three home runs in a 6-3 victory. It was Pittsburgh’s fifth straight loss and the club’s 11th in 13 games since the All-Star break.

• Box score

“We haven’t played winning baseball. We haven’t connected the dots,” manager Clint Hurdle said. “We haven’t been able to get our hitting and our pitching and our defense all synced up.”

The Bucs have fallen 10 games under .500 for the first time since the final day of the 2017 season. In the National League, only the rebuilding Marlins have a lower winning percentage.

Once optimistic about their odds of supplementing their roster prior to the Trade Deadline, it now seems as if general manager Neal Huntington will spend the next few days fielding offers with an eye on next year and beyond. There aren’t many game-changing reinforcements coming from within soon, either, as the club recently received discouraging news regarding Opening Day starter Jameson Taillon and right fielder Gregory Polanco.

“We talk about it all the time in here: When you’re down and things aren’t going the right way, you’ve got to continue to fight the same way you would if you were on a winning streak and playing really well,” starter Joe Musgrove said. “One game could be the turning point in the season. One game can turn things around for us and start a hot streak. We’re going to continue fighting.

“I don’t think anyone’s hanging their heads in here. It doesn’t feel good getting swept at home, but we’ve got a lot of baseball left, so we can’t dwell on this. We’ve got to move on and look forward to what’s next.”

The Cardinals, who moved into a tie with the Cubs atop the NL Central, look to be heading in the opposite direction. First baseman Paul Goldschmidt, surprisingly so-so at the plate in the first half, homered in all four games of this series -- and he’s homered five times in the Pirates’ last five meetings with the Cardinals. In seven matchups since the All-Star break, the Cardinals have put up 44 runs to the Pirates’ 27.

“They’ve been banging the ball against us,” Hurdle said. “They caught fire collectively from top to bottom.”

Goldschmidt was one of three Cardinals to take Musgrove deep on Thursday afternoon. Coming off an excellent start against the Phillies, Musgrove struggled to put away the Cards as he allowed seven hits and struck out only two over five innings. The Cardinals fouled off 21 of Musgrove’s 89 pitches while only swinging and missing on three of them. Musgrove said he struggled to locate his slider for strikes, so the Cardinals eventually stopped chasing it. That led to a handful of costly mistakes within the zone.

Goldschmidt blasted a changeup out to center in the fourth inning, and Kolten Wong hit a low curveball out to right two batters later to put the Cards ahead, 4-1. After Tommy Edman reached on an error by Josh Bell in the fifth, Dexter Fowler launched a high sinker into the center-field shrubbery to give the Cardinals a five-run cushion.

“The homer was what killed me today,” Musgrove said. “Getting runners on base and not being able to execute pitches, and ultimately the long ball was really what hurt.”

The Pirates managed to scratch across three runs against Cardinals starter Miles Mikolas. Starling Marte showed no signs of slowing down as he hit an RBI double in the sixth and scored on a groundout by Colin Moran, but Pittsburgh went out quietly against the St. Louis bullpen.

All-Star first baseman Bell said the Pirates can only “collect good energy” and “hunt the good” rather than focusing on everything that’s gone wrong, but it hasn’t just been one phase of the game that’s led to this slide by the Pirates.

During their 12-5 stretch from June 19-July 7, the Pirates posted a 4.18 ERA while scoring 6.6 runs per game. Over the last two weeks, their ERA has gone up more than a run to 5.24 while their offensive output has been cut nearly in half to 3.4 runs per game.

At some point, the Pirates have to believe, it’ll turn back around.

“We’ve got a lot of baseball left. I’ve seen a lot of crazy things happen in this game,” Musgrove said. “Last year, we went on an 11-game win streak. We get hot at the right time, other teams fall off, we’re definitely not out of this thing yet. We’ve put ourselves in quite a hole here, but we’ve got to keep plugging every day.”