NEW YORK -- Indians manager Terry Francona said that he and bench coach Brad Mills had gone back and forth, debating whether to start Oscar Mercado in left field or center field before Tuesday’s opener against the Mets.

Because Greg Allen had played the last four games in center, Francona decided to keep the consistency rolling, penciling Mercado into left. But little did the rookie know that he was in for a long night in the Indians’ 9-2 loss to the Mets at Citi Field.

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In the third inning, Joe Panik hit a fly ball toward the left-field corner that Mercado got a decent jump on. But as he approached the line, a fan in foul territory reached over the wall and made the catch, robbing Mercado of an opportunity to make an out.

“I thought I had a chance,” Mercado said. “But he reached over and didn’t really give me a chance. I guess we’ll never know.”

The play brought Francona out of the dugout to chat with home-plate umpire Mike Everitt.

“They’re hard dugouts to see down the lines,” Francona said. “I didn’t know if he called interference or obstruction or whatever, so I went out and said, ‘Hey, can you guys look at that?’ And he said, ‘Well, we have.’ He goes, ‘Do you want to contest that he could have caught it?’ So that’s why I went to the dugout to ask Millsie, and it was real iffy so we decided not to.”

But the fan didn’t go away quietly. The spectator kept chirping in Mercado’s direction, yelling so much that when he got escorted out of his section, the Indians outfielder bid him farewell with a wave.

“Yeah, he just started yelling in my face,” Mercado said. “So then I just looked at him and kind of started laughing, and when he got ejected -- it’s pretty funny to me. But I guess they had the last laugh.”

Mercado’s sense of humor then faded in the sixth. For the third time in the past three games, the 24-year-old outfielder committed an error in left field, dropping a routine fly ball. With one out, Panik lifted a curveball to left field with a launch angle of 62 degrees and an exit velocity of 86.2 mph, resulting in a .010 expected batting average, according to Statcast. The ball popped in and out of Mercado’s glove.

“I just dropped it,” Mercado said. “I don’t think anything really happened. I had it just like every other fly ball I’ve caught in my life, but it just popped out of my glove.”

“Oscar did everything right,” Francona said. “He just didn’t catch it. He called [shortstop Francisco Lindor] off. He didn’t look away. He just missed it. That’s gonna happen.”

Shane Bieber struck out the next batter, which would have been the third out of the inning if not for the error, and then Michael Conforto delivered a two-run homer to break a 2-2 tie that began a domino effect for the Mets’ offense, which loaded on five more runs in the next two innings.

“They’ve picked me up numerous times,” Bieber said of his defense. “I felt like I should be able to do that and almost did, just didn’t get the pitch where I wanted to. I wanted to bury it and left it up. Down and in to a lefty, and [he] took advantage of it and put a good swing on it. But I felt confident enough to go out there and make pitches and pick them up just like they’ve picked me up all year.”

Of Mercado’s six errors this season, four of them have come in left field, but the natural center fielder said switching positions isn’t something that’s too challenging for him.

“I think I have to just be ready,” Mercado said. “I have to do a better job of being prepared defensively out in left field and take it with the same pride and focus that I do out in center.”

“It’s definitely a learning process,” Allen said. “He’s learning, he’s growing and I’m doing the same. If you ask any guy in here, we’re all doing the best to get better. It’s definitely one of those things that you learn from, grow from. He’s an incredible outfielder, incredible defender, just an all-around athlete. Again, it’s the game of baseball. We’re all human and those things happen.”