Listen to article • 0:00 min

MIAMI — As the offense poured on six runs in the first five innings, it felt like the Phillies were back on track, at least for the moment.

But it didn’t take long for another of the team’s weaknesses to become magnified.

The Phillies’ latest pitching collapse led to an 8-6 loss to Miami on Wednesday, squandering a game they had once comfortably led 6-0. The Marlins had started the series on a franchise-record 12-game losing streak, and they ended it by sweeping the Phillies out of South Florida.

“We’re just not playing complementary baseball,” said Trea Turner. “Feels like when we hit, we don’t pitch as well, and when we pitch well, we don’t hit. It’s just frustrating.”

» READ MORE: Don Mattingly on Bryce Harper’s belief the Phillies need ‘help’ at deadline: ‘Players like being GMs’

In a pivotal spot in the seventh inning, interim manager Don Mattingly opted to go with righty Seth Johnson, and he struggled to command his pitches. After he left a slider up in the zone for Xavier Edwards, who capitalized with a two-run single, the Marlins had come all the way back to tie it at 6.

The Phillies have played 29 one-run games — over a quarter of the season so far — and they have taken their toll on the back end of the bullpen. Both Orion Kerkering and José Alvarado were unavailable Wednesday after pitching two nights in a row. That left Jonathan Bowlan as the highest-leverage arm available, outside of closer Jhoan Duran.

When Mattingly went to make a pitching change for starter Jesús Luzardo with one out in the seventh, he decided to save Bowlan for the eighth, even though the tying run was already on first.

“Trying to get a short amount of outs [for Johnson], compared to Bowlan trying to get more,” Mattingly said.

When Bowlan did enter in the eighth, now in a 6-6 game, Miami delivered the knockout punch. Pinch-hitting Griffin Conine — who had walked off the series opener against Duran — sent a two-run homer out of the deepest part of the ballpark.

The collapse stung all the more because the offense had shown some promising signs early. By the end of the third inning, the Phillies had already matched their hit total of four from the night prior. And unlike in Tuesday’s 1-0 loss, they had some runs to show for it, after Bryson Stott’s double drove in two.

The Phillies tacked on another run in the fourth with a sacrifice fly, and sparked another rally in the fifth. Turner, who started at designated hitter with Kyle Schwarber unavailable due to a gastrointestinal illness, started things off with a solo homer.

» READ MORE: The Phillies must go through the Dodgers. To do it they’ll need to find a lefty reliever at the trade deadline.

Stott walked, before Harper tucked an RBI triple just inside the right field foul line. A single from Alec Bohm brought Harper home, but that would prove to be the Phillies’ final hit of the day.

“We expect better of ourselves,” Turner said.

Even so, a 6-0 buffer should have been plenty for Luzardo. While the bullpen has been a weakness for the Phillies for most of the season, their top three starters have been relied on to carry the load. And Luzardo was cruising early against his former team, until a lapse in the fifth helped Miami halve the Phillies’ lead.

Esteury Ruiz hit a leadoff double, advanced to third on a sacrifice bunt, and scored on an RBI groundout. Luzardo also hit Miami’s No. 8 hitter with a pitch, but he was a strike away from getting out of the jam when Heriberto Hernández blasted a two-run homer on a 3-2 changeup elevated in the zone.

“My own fault,” Luzardo said. “Lefty on deck, I had a lot of things in my mind. Probably should have thrown something else, or been a little more aggressive with it. And that’s why I was kicking myself afterwards, just knowing who was on deck and just giving in on a 3-2 pitch.”

He got into more trouble in the seventh. Ruiz started things off again, this time with a leadoff single. He stole second and then advanced to third on a throwing error by catcher J.T. Realmuto.

The key at-bat came against Miami’s nine-hole hitter, lefty Jakob Marsee. Luzardo jumped ahead in the count 1-2, but ultimately lost the battle by issuing a walk. It turned the lineup back over to Otto Lopez, who singled off a changeup below the zone to score another run and end Luzardo’s day.

“Frustrating,” Luzardo said. “We knew they were going to come out a little hungry after losing 12 in a row. But I mean, just frustrating the way it happened.”

» READ MORE: With the trade deadline looming, Bryce Harper says Phillies ‘need some help’

After Miami tied the game, the Phillies offense had no response. They went down in order in the eighth and ninth inning to seal their latest deflating loss.

This marks the first time the Phillies have been swept in a series since their 10-game losing streak in April, which cost Rob Thomson his job as manager. But this skid feels a little different.

For one thing, time is running out.

“Earlier, those things happen, you try to learn from it, and now at this point in the year, you gotta find a way to win ball games,” Turner said. “And it’s kind of go time. So got to figure it out.”

There surely will be changes to the roster in the coming days as the trade deadline approaches on Monday. But for Mattingly, now is when the true test of his club begins.

“Now’s the time that we’re going to find out what we’re made of,” Mattingly said. “We’ve been through a struggle. We’ve let everybody stay in the race. So we find out who we are over these next couple of months.”