Unlock Boxers:
     Enter these as your name in career mode:

NELSON            Trevor Nelson
DEFIAGBN          David Defiagbon
MRBARRY           Barry Sanders
OSUNA             Bernando Osuna
HATCHER           Charles Hatcher
ZITO              Chuck Zito
MECCA             Ashy Knucks
OWNOLAN           Owen Nolan
AUSTIN            Ray Austin
JRSEAU            Junior Seau
SBATISTE          Muhammad Ali
BOSTICE           David Bostice
JBOTTI            John Botti
STEVEF            Steve Francis
DEMART            David DeMartini
JGIAMBI           Jason Giambi
BAILEY            Joe Mesi 

Illegal moves:
     During a game, hold R1 + R2 and press one of the following:

X = Low punch
Circle = Kidney punch 
Triangle = Head butt 
Square = Elbow
Triangle + Circle + X + Square = Bite ear