MIAMI – As a starter, Carlos Hernández possesses a reliever mentality. That’s one reason the Royals’ 26-year-old right-hander trotted in from the bullpen in the bottom of the first inning against the Marlins on Monday at loanDepot park.

Even as an opener, Hernández keeps a reliever's mindset.

“Nothing really different,” Hernández said through an interpreter. “Just coming out of the bullpen, not changing anything. Just treat it as a relief appearance, and do a job.”

Hernández was a bright spot in an otherwise frustrating 9-6 loss to the Marlins in a game in which a four-run early lead slipped away.

In his opener role, Hernández retired all six batters he faced in dominating fashion, striking out three and throwing 19 of his 23 pitches for strikes.

“It doesn’t get much better than the way he threw the ball today,” manager Matt Quatraro said. “He had an electric fastball. He was getting swings and misses on his offspeed as well. He was in the zone the whole time.”

Hernández showcased a fastball that topped at 99.7 mph. Yet, his future may be as a closer, or certainly a high leverage reliever.

“We think so highly of him towards the back end of the game in the future,” Quatraro said. “Part of the development process is understanding that you can face the top or the middle of the order out, and you can do it in the first or second, it’s no different than doing it later in the game, where you don’t have as much of a safety net behind you.”

Five of the eight swinging strikes he recorded came via his four-seam fastball.

“Individually, yeah, you feel good,” Hernández said. “But we still didn’t get the win. As a teammate, you never really feel good. Individually, it went well.”

Hernández has been dealing with a callus on his right thumb. He admitted it bothered him a little in the second inning, but that wasn’t reflected in his crisp performance.

“The guy that started was pretty good,” Marlins manager Skip Schumaker said. “So I'm glad he didn't keep going through six or seven innings, because he had some good stuff and kind of blew our doors off a little bit.”

The Royals struck quickly off Marlins lefty Braxton Garrett for two runs in the first inning. Nick Pratto singled to open the game, and scored on MJ Melendez’s RBI double. Salvador Perez followed with a run-scoring single.

In the third inning, Pratto hit a leadoff homer, Bobby Witt Jr. reached on an infield single and Melendez delivered an RBI single, making it 4-0.

Melendez, who is from Miami, had a strong night in his first big league game at loanDepot park, where he participated in the World Baseball Classic.

“Good time, always,” Melendez said. “Pretty cool being in Miami. My first time playing here, in an MLB game. It was really exciting. I had a blast.”

When Hernández exited in the third inning, the Marlins mounted their comeback off Mike Mayers, who was coming off working six-plus scoreless innings against the Cardinals. In that outing, the right-hander threw six perfect innings before allowing two hits after coming out for his seventh inning, where he didn’t record an out before exiting at 76 pitches.

But on Monday, Mayers was tagged for seven runs (six earned) on nine hits in three innings.

“I gave up seven runs in three innings, so not a good day,” Mayers said. “I thought I made some quality pitches early, and they took them or put the barrel to the ball. They had a good approach against me. It can’t happen.”

In the third inning, Joey Wendle doubled and scored on Jonathan Davis’ fielder’s-choice grounder, and Luis Arraez slapped an RBI double to left, trimming Kansas City’s lead to 4-2.

After Mayers recorded two outs in the fourth inning, the Marlins strung together five straight hits. Jon Berti had a two-run triple, Davis delivered an RBI double, and Arraez slapped a run-scoring single, giving Miami a 6-4 advantage.

Mayers was charged with an unearned run in the fifth inning when center fielder Drew Waters dropped Yuli Gurriel’s fly ball for a two-base error. Nick Fortes followed with an RBI single, giving Miami a 7-4 advantage.

“It is something at this level, you expect that play to be made 100 percent of the time, and I’m sure Drew will focus on that and do better the next time,” Quatraro said.