MIAMI -- With two outs in the third inning, Mets veteran southpaw Jason Vargas threw over to first base to keep opposing pitcher Caleb Smith honest ... six times.

Smith, who spent June on the injured list with left hip inflammation, certainly didn’t appear to be a baserunning threat. Plus, Vargas had already gotten ahead in the count against Curtis Granderson.

But what started as a one-run cushion quickly became a two-run deficit when Vargas surrendered back-to-back homers in that frame in Friday night's 8-4 loss to the Marlins at Marlins Park to open the second half. The Mets dropped to a season-high 11 games under .500.

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“I didn’t think he was going to steal at all,” said Vargas, whose six runs allowed in five-plus innings were his most since June 19, 2018. “If we caught him going, or them moving him to stay out of a force play, that would’ve been great. It takes a little bit out of you to dive. [That] had more to do with it than thinking that he was going to steal. I was trying to take advantage of him putting himself in a situation where he's going to have to work harder. I didn't make the pitch that I needed to make.”

With the Mets ahead 2-1 after the Marlins scored a run on a Miguel Rojas sacrifice fly prior to Granderson’s at-bat, Vargas ran the count full with his attention distracted by Smith. He then left a changeup over the plate that the former Met sent over the wall to score two runs, negating the two runs New York scored in the top half of the frame and putting the Marlins ahead, 3-2. In the next at-bat, Garrett Cooper followed with a tater to make it a four-run inning.

“I think the big problem was missing that fastball away to [Granderson for ball three] and setting it up to give him something to look out for, and not making a pitch,” said Vargas, who admitted he doesn’t normally attempt that many pickoff throws.

Added Smith: “That was awesome. I was standing on first. After the third or fourth pickoff, [first-base coach Trey Hillman] came over there and he mentioned, 'He's about to hit a homer right here.' And it happened.”

In his last start, on July 3 against the Yankees, Vargas did something similar -- but got better results -- with DJ LeMahieu on first base and Aaron Judge at the plate in the fifth inning. With the count 0-2, he threw four straight pickoff attempts in a five-pitch at-bat that culminated in a strikeout.

“We talked about that. Sometimes it can interrupt the flow of the game,” Mets manager Mickey Callaway said. “What he was trying to do tonight is, the pitcher kept getting off pretty far, and if he was going to keep diving into the bag, Vargas wanted to make him dive as many times as possible.

“After that, we talked about what you’re talking about. That’s all well and good, and I understand that, we just can’t let it throw ourselves off. When you’re out there pitching, the rhythm of the game, the flow of the game matters a lot, especially when you try to make pitches. Unfortunately, when we did that, we threw ball, ball, then gave up a homer. Who knows if it was because of that, but we do need to pay attention to that.”

The 36-year-old Vargas entered Friday with a 2.76 ERA over his past 12 starts, having given up three earned runs or fewer in each outing to boost his stock as the Mets look to be sellers before the July 31 Trade Deadline. With 14 years in the big leagues and postseason experience under his belt, he would likely fetch a minor piece in return.

Vargas, who is making $8 million in 2019 and has an expiring contract with a team option for the same amount next season, admitted to not being as sharp as he had been during that stretch.

“I thought he threw the ball pretty good,” Callaway said. “Couple of pitches he'd like to have back that led to some runs, but overall, it was the same old Vargas.”