PORT ST. LUCIE, Fla. — Seth Lugo “absolutely” believes the 2017 Astros’ cheating changed the course of his career, he said this week. And he cannot help but wonder if he still might be a starting pitcher had Houston played fairly that year.

The biggest story in baseball during the offseason became the biggest story of a new season in recent days, with spring training camps opening across Florida and Arizona, and Lugo is among the dozens of major-leaguers who have aired grievances regarding the Astros' sign-stealing scandal.

“The whole idea of cheating to win — I don’t understand how people cheat,” Lugo said. “I just don’t understand how it makes you feel good.”

Lugo’s cameo in this saga came on Sept. 2, 2017, in the second game of a doubleheader in Houston. As the Mets limped to the end of a losing season, Lugo was in the rotation, a de facto audition for 2018 — invaluable reps for a second-year player trying to establish himself in the majors.

For five innings, Lugo managed to shut out the Astros, scattering five hits and a walk. Then came the bottom of the sixth: single, walk, single, single. Just like that, one of the best starts of Lugo’s young career was over after 75 pitches.

“I remember pitching really good the first half of the game, and then I don’t know why, they knocked me out of the game in one inning,” Lugo said. “I pitched that inning. I was making good pitches. And when you execute a pitch, you shouldn’t give up good hits. Maybe a little bloop or a ground ball up the middle or something. But their whole approach changed.”

Hansel Robles entered and allowed both inherited runners to score, including one on a sacrifice fly by J.D. Davis, now with the Mets. Lugo’s final line wasn’t pretty: five innings, eight hits, four runs (all earned), two walks, six strikeouts.

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What Lugo didn’t know at the time was that the Astros were using an illegal system for stealing opposing teams’ signs that season. An investigation by Major League Baseball found Houston guilty of using a camera in centerfield and a monitor near the dugout to observe a catcher’s calls, then communicating that information to the batter at the plate via bangs on a trash can.

The next day, Lugo said, Mets coaches told him “we don’t think you should start anymore,” in part because of struggles the third time through the lineup.

“Well, not in those exact words,” said Lugo, who couldn't recall the exact conversation from more than two years ago. “That’s how I took it.”

Lugo rounded out the month in the rotation, pitching fine but with abbreviated pitch counts. The Mets told him they were trying to protect his arm. (That season began for Lugo with a partial tear of the ulnar collateral ligament in his right elbow.) He said the most frustrating part of knowing what he knows now is that, in those waning days of the 2017 season, he changed his approach at times, based on feedback from that sixth-inning disaster in Houston.

“That’s the tough part for me with this,” he said. “Should I have actually done something different, or should I have kept doing what I was doing and I would have actually had more success?”

The next spring training, Lugo ostensibly was in a competition for a rotation spot, and the Mets even said he won one. But he got moved to the bullpen before taking a turn and has been there almost exclusively — to great success — ever since.

Lugo, who has been persistent but professional for years about his preference to start, is destined for the bullpen again this season. He got squeezed out of the rotation by the signings of Michael Wacha and Rick Porcello in mid-December. There was early offseason talk of Lugo being a starting option, but after the Mets added Porcello, he said, they told him he would remain a reliever.

When news of the Astros’ cheating broke in November, his mind went right to his game against them. Although Davis and Jake Marisnick, also a 2017 Astro, are Lugo’s teammates now, he said he doesn’t feel a need to talk with them about it.

“It doesn’t feel good thinking about the Astros situation, but it’s in the past, honestly,” he said

And yet he wonders about the what-ifs.

“If I could’ve finished a shutout against the Astros that game,” he said, “who knows where I could be?”