Jon Niese waited until hours before the Mets broke camp to have his best moment of spring training. After throwing 59 pitches in a minor-league exhibition Thursday while his teammates were playing the Nationals in a Grapefruit League game, Niese said the left-elbow soreness that derailed him in his last start was no longer an issue. “There was kind of a little bit of worry, just because I haven’t pitched in a game to where it didn’t hurt, and today it felt amazing,” Niese said. “It felt like it felt at the end of last year. I’m ready to go.” Niese will remain in Florida to make what he hopes will be a final minor-league exhibition appearance, on Tuesday. That start would be Niese’s final hurdle to clear before facing the Reds on April 6 at Citi Field. Ideally, Niese would like to throw 75 pitches in his final minor-league exhibition. The Mets would like to have him available for 90 pitches when he makes his first major league start of the season. The left-hander showed good velocity on Thursday, according to pitching coach Dan Warthen. That meant a fastball in the 89-91 mph range and a cutter that was thrown between 86 and 88. “So we were pretty much where we wanted to be,” Warthen said. It was a lag in velocity that may have caused Niese’s recent soreness. He left his exhibition start against the Cardinals on March 16 after just two innings with elbow soreness that he says probably stemmed from trying to overthrow because he was unhappy with his previous radar-gun readings.