New York Mets fans began the year dreaming about a World Series closed out by Edwin Díaz. For now, they’re facing a nightmare scenario. In a startling scene, Díaz was taken off the field in a wheelchair after injuring his right knee celebrating Puerto Rico’s victory over the Dominican Republic in the World Baseball Classic on Wednesday night. There was no immediate word on how severely Díaz was hurt. The Mets said he will undergo more tests Thursday. But the injury was exactly what big league teams and their fans fear the most when their high-priced stars go play for their countries. Díaz was swarmed by teammates after pitching a perfect ninth inning in a 5-2 win. The group was jumping together when Díaz collapsed to the ground.