NEW YORK -- When Marcus Stroman joined the Mets last summer, the returns were not initially strong. Over his first seven starts with his new team, he posted a 5.05 ERA with a .320 opponents’ batting average -- numbers that the right-hander attributed to an adjustment period moving from Toronto to New York.

The correction occurred over his final four starts, when Stroman went 3-0 with a 1.88 ERA, now setting himself up for the most critical 60-game stretch of his career. For the first time, Stroman is set to hit the open market this winter at age 29, joining Trevor Bauer and Robbie Ray at the top of the free-agent starting pitching class.

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“I’ve been playing year-to-year my entire career, essentially, so I’m looking forward to being settled,” Stroman said. “I truly believe that I’m going to be an untapped potential once I’m truly settled and know I’m not going anywhere for that year. … I think that’s going to do wonders for my mind, my body, my pitching ability -- everything. I truly believe my best years are ahead of myself.”

Whether the Mets might have interest in retaining Stroman longterm will depend in large part on how he fares over the 60-game season. When Noah Syndergaard underwent Tommy John surgery in March, it bumped Stroman from third to second on the Mets’ depth chart behind only Jacob deGrom. At times in his career, Stroman has pitched like a No. 2 or better, most notably when he produced a 2.96 ERA for the Blue Jays last year before the trade. At times, he has not -- a 5.54 mark during his injury-laden 2018 season, for example.

During the shutdown, Stroman appears to have done everything possible to ensure that 2020 will see him trend toward the former pitcher and not the latter. Working out at his home in Florida, Stroman believes he added arm strength long tossing in his front yard. He constructed a bullpen mound on the dock overlooking the water. He worked out with teammate Dominic Smith in his home gym. He frequently spent time in a hyperbaric chamber. He invited his personal trainer, former Blue Jays head trainer Nikki Huffman, over to work with him daily.

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The result? A confidence boost for someone who was already one of the most self-assured men in baseball.

“I feel like I’m in the best shape of my career, honestly,” Stroman said. “I feel stronger. I feel just as mobile, just as flexible, just as fluid, but I feel stronger. My arm feels stronger. I train extremely hard. Extremely hard. So I know I’m going to be in this game for a long time.”

“This guy brings such a positive attitude to the clubhouse, such a positive attitude to the game as well,” added Mets manager Luis Rojas. “In between the lines, you’ve seen his energy how he goes. As soon as he became a Met last year, you guys saw how the team also had a little bit of that push toward the end.”

Stroman’s first intrasquad appearance on Sunday was far from perfect; he walked the first three batters he faced and allowed a stolen base before Mets coaches ended the inning prematurely so that his pitch count would not rise too high. What will matter far more is what happens when Stroman appears in his first regular-season game later this month. On the mound, he plans to make his four-seam fastball a focus this season, throwing it up in the zone more to add strikeouts to what has always been a ground ball-dependent pitching profile.

The idea is to become even more of a complete pitcher -- both to help the Mets this season and also to cash in through free agency when it ends.

“It will truly play out how it will play out,” Stroman said. “I think I should be one of the top arms. I believe I’m one of the youngest. I’ll be 29. I’m extremely healthy. I’m coming off a great year. So however it plays out … I’m truly focused on just being in the moment now, and doing everything I can to take this team to the playoffs.”