The whole point of Master League, as in every previous ISS, PES and WE game is to start with a bunch of nobodies (whichever team you choose) and buy the players you want.
You have to wait till the end of the first season to make transfers in WE7 & PES3. Offers will come in for your players after that. If you have a good translation patch, you should be able to find out where the ML transfers option is. If not, get one of the 100% translation patches.