 The player 's team receives randomized , team @-@ specific textual messages in between games , including offers for free agent offers , training sessions , drugs , bets on the player 's performance , and events including accidental gifts from the player 's manager , threats from the team 's owner , and organized crime extortions . Players can buy character attribute increases with their credits . Single @-@ player progress unlocks concept art and game assets external to the game , as well as new teams , players , and arenas . Each of the unlockable 13 teams has six unlockable players ( for a total of 10 players on each ) , and five additional legacy teams are limited to four players apiece . Multi @-@ disc and " Extreme " difficulty gameplay options are also unlockable . 
