How do you hit homeruns in "The Bigs" PS2?

Hi, can anyone help me with this game. The Bigs from 2ksports for the PS2. How do you hit homeruns (not using power blast). I've been using Boston's Ortiz and Ramirez and although they have 5 star power they seem to be nothing more than glorified Doubles hitters.. please help me. Thanks.