Springfield Mayor Domenic Sarno said “the fan experience will be much, much better” at the MassMutual Center after the state’s investment. They’re smart investments for the MassMutual Center. They’re smart investments for Springfield. They’re smart investments for Massachusetts,” Healey said. Before heading to another announcement at the CRRC train-assembly factory in Springfield, Healey pledged her support to Springfield, the state’s third-largest.