Right-hander Frankie Montas, one of the New York Mets’ new starting pitchers, will miss 6-8 weeks with a high-grade lat strain, the team announced on Monday.Montas will leave the Mets’ spring training facility in Port St. Lucie, Fla., and go to New York for a platelet-rich plasma injection. The shutdown means he might not join the Mets until May or June.”He’s going 6-8 (weeks) with no throwing,” manager Carlos Mendoza said. “Ramp up, he’s pretty much gotta go through a whole spring training program.”Montas, who turns 32 on March 21, signed a two-year, $34 million contract with the Mets in December, with the player having an opt-out next December.