Mets pitching phenom Matt Harvey rocks off the mound, too. He’s become pals with Ranger goalie Henrik Lundqvist, an accomplished guitarist, and the friendship has brought out Harvey’s hidden singing talent. “We were hanging out one night,” Harvey told Gotham magazine. “I mixed in a couple of singing lines, and he actually asked me into the studio [to record] with him . . . hopefully we can make that happen.” Lundqvist’s jammed with John McEnroe and played on Jimmy Fallon’s show.