NEW YORK -- For weeks, Steven Matz drove back and forth to the Mets’ alternate training site on Coney Island, battling traffic as he labored to fix what ailed him. Initially, he was working to get his left shoulder right following a bout of bursitis in early September. Once he grew healthier, the focus changed.

 In simulated games, Matz refined his pitch sequencing, aiming to remain unpredictable to opposing hitters. During side sessions, he tried to perfect his command. The Mets remained enamored with his stuff -- mid-90s fastballs and big, bending curveballs in the line -- but not with his results.

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By the time Matz returned to a big league mound on Friday, both he and the Mets were eager to see his gains. Instead he allowed six runs to the Braves in 2 2/3 innings, sending the Mets to a 15-2 loss that further dampened their postseason hopes.

“It always comes down to executing pitches,” Matz said. “The sharpness wasn’t there. Executing pitches wasn’t there. I gave those guys a chance, and they capitalized.”

Most of Matz’s old problems, including his propensity to allow big innings, surfaced once again. Matz allowed hits to the first three batters of the night, including an RBI single to Marcell Ozuna, though he recovered to strand the bases loaded in the first inning. In the second he wasn’t so fortunate, serving up a two-run double to Freddie Freeman and a two-run, second-deck homer to Ozuna.

“The command hasn’t been there,” manager Luis Rojas said. “The execution of the pitches, the sequencing … made it big innings against him. From the first inning basically, that was happening to him, where he was not able to execute his pitches.”

That the Mets asked Matz to rejoin the rotation was mostly a matter of necessity, with so many other starting pitchers struggling. Why not give Matz, whose talent has tantalized the Mets since they made him a second-round Draft pick more than a decade ago, another chance? For years, Matz represented more potential than finished product, largely because injuries interfered with his development. But he delivered 60 starts from 2018-19, posting a 4.09 ERA and a roughly league-average adjusted ERA+.

“His stuff is one of the things we like a lot -- the fastball velo, the changeup, the contrast that he can create, the angle of his pitches,” Rojas said.

Why Matz has struggled to put it all together remains a mystery to Mets officials, who have long watched him deliver solid outings only to allow -- often without warning -- multi-run rallies. But the team has little choice but to keep trying. Heading into next season, Jacob deGrom is the only surefire member of the rotation. Seth Lugo could also play a role provided the Mets think he’s better served as a starter than a reliever. So should David Peterson, assuming he establishes himself as one of their five best options.

 From there, it’s anyone’s guess. Noah Syndergaard seems unlikely to be ready for Opening Day as he continues to rehab from Tommy John surgery. Marcus Stroman is about to become a free agent. The Mets will dip into the market for multiple starting options this winter, but whom they acquire will depend in large part upon a new ownership situation.

Which brings the team back to Matz. Part of the reason why the Mets started him this weekend is because they were hopeful, if not downright optimistic, that he could establish some sort of momentum heading into the offseason, proving himself as a bona fide rotation option -- or at least something close to it -- for 2021. Matz is one of the longest-tenured Mets, a homegrown arm, a well-liked teammate and an active member of the community in both New York City and on his native Long Island.

 Many are rooting for Matz to succeed. But one start into this latest experiment, he has only increased the volume and intensity of the questions surrounding him.

“It’s been a frustrating year for me,” Matz said. “I came into Spring Training 2.0. I was feeling great. I pitched great early on. For it to go this way is really frustrating. … I’ve just got to keep working hard. All I can do is keep putting my best foot forward.”