How to play MyCareer on A Custom Roster.
1. Go to your customized Roster in your saves folder. (C:/Users/*ur pc username*/AppData/Roaming/2K Sports/NBA 2K14/Saves).
2. Right-click your customized roster and click Rename (Keyboard Shortcut: Menu Key (the one between Alt and Ctrl) +M).
3. Rename the roster to Roster.ros.
4. Go to the game.
5. Load the Roster.ROS using Options.
6. Go to MyCareer and start playing.
Hope u enjoy!