Zack Wheeler isn’t headed to the bullpen just yet. The Mets right-hander certainly hasn’t earned a job in the team’s potentially crowded starting rotation, but a club source called a report Wednesday that indicated a decision has been reached and Wheeler was headed to the bullpen “way premature.” Wheeler will get the start Friday for the Mets in their Grapefruit League opener against the Braves at First Data Field. “He’s definitely a starting pitcher,” manager Mickey Callaway said. “For us to be the best possible team we can be we have to have him be a starter. He is going to go out there and do everything he can to win this competition we have going on.” Jason Vargas’ addition on a two-year contract worth $14 million last week gave the Mets at least six starting pitchers for five spots. Vargas, Noah Syndergaard and Jacob deGrom are virtual locks for the rotation if healthy, leaving Matt Harvey, Steven Matz and Wheeler in the mix for the remaining two openings. In addition, the Mets have potential starters in Seth Lugo, Rafael Montero and Robert Gsellman. At least two members of that group could end up in the bullpen (Montero doesn’t have minor league options remaining, giving him a huge advantage in making the team).