Finally, Travis d’Arnaud just had to jog out to the mound. Three batters into his first time catching Matt Harvey, the Mets’ battery of the future needed to make sure they started out on the same page. “I think I wanted to throw a (fastball) inside and he was calling everything but that,” Harvey said with a laugh. “You know it will take time, but he’s a good kid, he’s smart and willing to learn. I was very comfortable throwing to him.” Two of the cornerstones of this franchise’s future — d’Arnaud, the catcher they traded Cy Young Award winner R.A. Dickey away for, and Harvey — will be expected to figure out a relationship that will work for years to come. They took that first step together Sunday in a Grapefruit League game that ended in a 7-7 tie against the Astros at Osceola County Stadium. After posting a 2.73 ERA in 10 starts as a rookie in 2012, Harvey, the Mets’ first-round pick in 2010, came into spring confident. Sunday he pitched two innings, giving up one earned run, a home run to former Met Fernando Martinez. He allowed two hits, walked one and struck out three. Harvey threw 39 pitches, 25 for strikes. The 23-year-old righthander gave up a leadoff single to shortstop Marwin Gonzalez, who stole second with one out and first baseman Carlos Pena batting. With a full count on Pena, Harvey was shaking off the young catcher repeatedly, until finally d’Arnaud ran out to the mound. “I was just asking what pitch he wanted, it was a big hitter, Carlos Pena was up, a big moment, 3-2, and we needed the out,” d’Arnaud said. “And he executed his pitch and got him out.” Read more: