The Mario Fireballs are Mario's team in Mario Super Sluggers.In Mario Superstar Baseball, Mario has other names too. Mario's team is Mario, Luigi, Blue Noki, Green Noki, Red Noki, Blue Pianta, Red Pianta, Yellow Pianta, Blooper and the unlockable, Monty Mole. He can be unlocked by beating Challenge Mode with the Mario Fireballs.
Mario's team names are the Mario Fireballs because Mario can throw Fireballs, Mario Heroes because Mario is a hero, Mario Caps because Mario has a cap, Mario Plumbers because Mario is a plumber and Mario All-Stars ( See Super Mario All-Stars
Mario and Luigi, the Secondary Captain signs are Ms and Ls. The Mario Brothers abilities are Fireballs and Tornados.