When you buy the game, a lot of the best teams and players are disguised with fake names because Konami doesn't have the licences to use the real names. What some people do (awesome people to say the least) is create option files that you can load into your PS2 (or other game console) that fix all the fake names and use real names instead. Hence, the game is WAY more realistic. These people fix the names, the faces, hair, and a BUNCH of stuff to make the game, teams, players, etc seem as close to real life as possible.
Once an option file is available for your game version and game console (i.e. PS2, USA version), you need a max drive or other device to transfer the file to your PS2 (I'm only familiar with the max drive). You can buy a max drive from Best Buy or many other online stores. So, you download the file to your PC, move it to a max flash drive, put the flash drive in the USB slot of the PS2, load the CD that comes with the max drive into your PS2, and use the uncrush function to transfer the file to your memory card. Once that's done, when you load the game, the new option file will load and all the team names, player names, and all the fixes these awesome people did will be there. Game is so much more fun like that.
Look out for Petagato's thread on an OF file he's working on for the USA version of the game, but it will take some time. He will be your hero when he's done. lol. Hope this helps. Take care.