BOSTON -- Adam Duvall had just hit his latest moonshot on Monday night at Fenway Park to put the Red Sox ahead in the opener of a key three-game showdown against the Astros.

Things were looking up.

And then they weren’t.

As the Red Sox were routed, 13-5, to fall 5 1/2 games behind Houston for the third American League Wild Card spot, the big topic was manager Alex Cora’s decision to stick with reliever Kyle Barraclough throughout a nightmarish top of the sixth.

After the game, Cora explained that his bullpen is running on fumes amid a stretch in which the Sox have played 14 days in a row and haven’t received a satisfactory innings load from the rotation. Boston plays Tuesday and Wednesday before getting its first day off since Aug. 14.

“For us, it's tough,” said Cora. “But this is where we’re at. It’s 16 games in a row. And a lot of teams go through this and we just have to get over that hurdle. Right now for us, this is where we’re at. We’re going to be in better shape [Tuesday] bullpen-wise. Much better.”

After Duvall’s two-run rocket onto Lansdowne Street (his sixth homer in the last eight games) in the bottom of the fifth inning, the Red Sox had a 4-3 lead and needed 12 more outs to gain what would have been an important win.

In a vacuum, Cora likely would have gone to Josh Winckowski or John Schreiber in a situation like that.

But given the circumstances, Barraclough, who got the final out of the fifth inning in relief of Chris Sale, came back out for the sixth.

As the sixth inning started, nobody was warming up as a safeguard in case Barraclough, a journeyman righty, faltered. As the Astros teed off for six runs in the game-turning frame, nobody ever did warm up. 

“We had a lot of guys down,” explained Cora.

Would Cora have managed the game differently if Sale had been able to go six innings or so?

“He didn’t, so I can’t answer that question,” Cora said.

Barraclough pitched the rest of the night, totaling 4 1/3 innings in which he was tagged for 10 runs on 11 hits while walking five, striking out one and hitting three batters.

“I just didn’t have it,” Barraclough said. “One of those nights, I lost control. That’s about as bad as I think I’ve thrown the ball in my life.”

Barraclough expressed no qualms with Cora’s decision to keep him out there. In fact, Barraclough volunteered to go back out for the ninth when Cora was contemplating using a position player.

“No, not at all. That's why I'm here,” Barraclough said. “Those guys aren't supposed to be pitching and come in and clean up my mess. I pitched like crap. Go out there and wear it and make those guys fresh for the next day.”

Meanwhile, Houston, led by Jose Altuve’s first career cycle and a dominant four-hit night by slugger Yordan Alvarez, delivered the opening salvo in this three-game series.

Without question, Boston’s bullpen has been taxed of late. During these past 14 games without a day off, Boston’s starters have logged 66 2/3 total innings, for an average of 4.76 per start. That is the sixth-lowest innings pitched per start of any team in the Majors over that span.

In an effort to reset the bullpen, Cora kept Chris Murphy out there for four innings in Sunday’s loss to the Dodgers, even though the lefty was shelled for nine hits and six runs. The only other reliever who pitched in Sunday’s game was low-leverage righty Mauricio Llovera.

It turns out one day of rest didn’t suffice.

“We're still resetting today,” said Cora.

Nobody seethed more than Sale, who pitched well in his first start back from the injured list, but has been inconsistent in his last three.

“Just not doing my team, myself any justice,” Sale said. “It’s tough. I come here every day and put in a lot of work to not get a lot out of it. My teammates deserve better. They needed someone to step up big tonight. We were obviously gassed out in the bullpen and needed someone to come in and act like an ace and that’s just not what happened.”

Barraclough had to pay the price, and Cora didn’t like having to put his pitcher in that spot.

“It’s awful,” Cora said. “You saw me. Probably my face was all over TV. It’s uncomfortable.”