The order of your fighters will appear before a versus match, with "1", "2", or "3". You can select the first and second fighters of your team, and thus change the entire team order.
To select the first fighter, press LP + LK for the character marked "1", MP + MK for the character marked ''2'', or HP + HK for the character marked ''3''. Then, press the same button combos to select the second fighter. Press Start to continue.