Dodgers score seven runs in final three innings in 8-5 victory over Rockies

A night of hysteria at Coors Field started with an alarm. In the afternoon before an 8-5 victory over the Colorado Rockies, Dodgers closer Kenley Jansen placed a call to the team’s training staff. He was marooned at the team hotel “and didn’t feel right,” manager Dave Roberts said. Jansen worried that he was experiencing a recurrence of the irregular heartbeat that has plagued him in the thin air of this city on multiple occasions.

Jansen never made it to the ballpark Thursday. He visited a local hospital and underwent preliminary evaluations. The team placed him on a flight back to Los Angeles and scheduled an appointment with Jansen’s cardiologist. Roberts described Jansen’s condition as “stable.”

The absence of Jansen blew a hole in Roberts’ bullpen, which was exposed in the later innings of Thursday night’s game before being redeemed by the offense. But the result of one individual game mattered little compared with the fear of losing Jansen for a significant amount of time. Dodgers officials sounded hopeful but cautious about drawing conclusions before Jansen undergoes further testing.

“He’s feeling pretty normal right now, from what we understand,” general manager Farhan Zaidi said. “But obviously it’s too soon to tell any sort of timetable, or how long he might be out, until we get him fully evaluated tomorrow.”

Jansen had surgery in 2012 to correct an atrial fibrillation issue. He experienced shortness of breath and elevated blood pressure in Denver in 2015. He has been prescribed medication for the condition, and Roberts indicated that Jansen had his medication with him for this trip.

“Obviously, we’ve got to be very careful with it,” Roberts said. “And then you’re talking about altitude. That’s why we wanted to be proactive and get him back to [Los Angeles]. We’re holding out hope that it’s not too serious. In talking to the trainer right now, his mood is fine. You wouldn’t know the difference.”

Not having Jansen made a difference for the Dodgers on Thursday. Roberts felt compelled to use Pedro Baez to protect a two-run lead in the seventh inning. The outcome would surprise few who have followed Baez’s torturous career as a Dodger. He imploded in a four-run flurry, capped by a three-run homer by Rockies catcher Chris Iannetta. Roberts stuck with Baez as the Rockies stoked the rally, intervening only after Iannetta went deep.

The offense took Baez off the hook. Cody Bellinger tied the score with a two-run blast against Rockies reliever Seunghwan Oh in the eighth. Chris Taylor gave his team the lead with a solo shot against closer Wade Davis in the ninth. Brian Dozier added to Davis’ misery with a two-run homer later in the inning. In all, the Dodgers swatted five home runs in the final three innings.

“The long ball played big tonight,” Roberts said.

After six tidy innings, the game drifted toward mania. The first two-thirds of the night were relatively tame. Ross Stripling, who had been bothered by a minor toe injury, returned from a 10-day sojourn on the disabled list to pitch six innings, giving up one run. He matched the outing of Rockies starter Tyler Anderson, who limited the Dodgers to one run in six innings. From there, the game spiraled.

“It got kind of crazy after I came out,” Stripling said.

It started in the top of the seventh when Joc Pederson and Max Muncy hit pinch-hit home runs. Pederson opened the inning against Colorado reliever Scott Oberg by drilling an 0-1 changeup for an opposite-field shot. Three batters later, Muncy did the same on a 97-mph fastball.

Muncy beamed as he returned to the dugout. The last few weeks have not been kind to him. After the All-Star break, when he competed in the home run derby, he had batted .183 with 27 strikeouts in 18 games. He shook off some of his slump Wednesday, when he singled and hit a few balls hard on the ground. On Thursday, he took to the air once more.

“When he’s using the big part of the field and going the other way,” Roberts said, “he’s dangerous.”

With Jansen sidelined, Roberts pondered his options to hold the lead. He was saving Scott Alexander for a save situation. He preferred to use rookie Caleb Ferguson against left-handed hitter. J.T. Chargois was not available. Dylan Floro had warmed up early in the game but did not enter, which made him unavailable after pitching the previous two days.

So Roberts chose Baez. He had not pitched in five days. He had logged two scoreless appearances in August. The third would be far less clean.

The Rockies staged a rally quickly. A leadoff single by third baseman Nolan Arenado preceded a walk of outfielder David Dahl. A single by first baseman Ian Desmond loaded the bases. Yasmani Grandal allowed a run to score for the second day in a row because he could not catch the ball, Arenado scoring on a passed ball. And then Iannetta crushed a 97-mph fastball off Baez.

“You’ve got to go out there and get outs,” Roberts said. “Fortunately for us, we battled back.”

The combination of the Dodgers power and the Rockies flammable bullpen proved explosive. After a two-out double by Matt Kemp in the eighth, Bellinger vaporized a 91-mph fastball from Oh. An inning later, after Ferguson completed a five-out assignment, Taylor and Dozier tormented Davis.

The victory was still tempered by concern about Jansen. The closer’s locker was untouched late Thursday night, his uniform hanging and his red Jordan sneakers awaiting his arrival. He will not wear the outfit this weekend at Coors Field.

“We’re just glad that he felt something and got help right away,” Zaidi said. “He’s feeling pretty normal right now, from what we understand. But obviously, it’s too soon to tell any sort of timetable, or how long he might be out, until we get him fully evaluated.”

andy.mccullough@latimes.com

Twitter: @McCulloughTimes