​Robert Stock’s impressive return to the majors was a bright spot for the Mets and the right-hander, so much so that it earned him another turn in the rotation.That turn came Saturday in Pittsburgh, and it was the opposite result for the 36-year-old.  Stock struggled with command and the Pirates put an eight-spot on the right-hander in the first four innings of the Mets’ eventual 9-0 loss. The combination of poor command and a pinch of bad luck got the better of Stock, and it cost the Mets any chance at extending their four-game winning streak.”Found himself behind in the count frequently,” interim manager Andy Green said of Stock’s performance after the game. “And by the fourth inning, he was out of gas. Had trouble commanding the baseball at that point in time. Forced us into a game that you’re in a bad spot in.”Stock’s day was over relatively early. The Pirates scored three runs in the first inning, which was helped by a misplay in the infield. With a runner on second and one out, Bryan Reynolds hit a soft grounder to Francisco Lindor. The shortstop, ranging to his right, scooped the ball up and looked to throw it to third base to try and get the lead runner. However, Bo Bichette was out of position and didn’t get back in time, allowing both runners to be safe.That play ultimately resulted in three runs being scored after a hit by pitch, an RBI groundout and a two-run double. “I experienced some bad luck early in it. That can be overcome by striking people out,” Stock said. “By the fourth inning, I look up the board just feeling my velo go down and my arm get tired.”Stock’s sinker, his go-to pitch on Saturday, was hitting 96.8 mph, according to Baseball Savant. By the fourth, it was down to 92.7 mph, and that turned the game. Entering the fourth, the Mets were down 4-0, but Stock seemingly settled down, but things took a turn for the worse as Stock walked batters and the Pirates teed off on his pitches, scoring four in the inning and putting the game out of reach.Stock said it wasn’t the number of pitches he threw — he tossed 80 on Saturday, the most he’s thrown in his major league career — but the pitches per minute. 
“I need to be more resilient to getting fatigued to not lose the count,” Stock explained. “Two things: if I execute pitches better early in the game, I won’t have to deal with the fatigue, and even if you do get fatigued, which is going to happen, you still need to fill up the zone.”After walking no batters in his five innings back on Aug. 2 against the Marlins, Stock walked five in his three-plus frames. That elevated pitch count and the deficit forced Green to punt on Saturday’s game. Xzavion Curry pushed through three innings and catcher Luis Torrens was called on to pitch two more to save the bullpen for Sunday’s series finale. “That was the worst part of tonight,” Stock said of the Mets having to go to the bullpen early. “When I got fatigued, I didn’t battle through it. I gave into it. That’s on me.” Green w