Hi 2 all. Siema byczek. Since not everyone knows how to put a player into the game I decided to put a little advise on how to put a new player.
First off all you have 2 download DB Commander from NLSC site.
When U got one open it choose "Open" and then go to your documents--->NBA Live 08--->Saves and then open the folder with your roster, pick file called "players" and open it.
Just like this one.

When u got this opened u have to provide data for your new player. For this go to
http://nbalive08.nba-live.com/index.php?go=dbf-players for more information and details.
The first couple of columns look like this.

When U will get to the column called "PlayerPKG" simple write "faceable cells in DBC" as Byczek said which for Tyler is: "TYTANHSB"
Like on this pic:

When U finished with "Players" U should open the "Appearance.dbf" and set the ID Player which for Tyler is 4180 (im using this one)
This should look like this one:

U have to set -1 to make the CF work in the game.
Please note i'm not like DB Expert. I learned the basics on my own experience and I'm not really sure this will work properly. TO successful U should follow the tutorials on the NBA-LIve page.
Im just trying to help!
take care