The type of game they are playing does not matter, all that matters is that they get 48+ minutes, or else they will get partial training. Training is based on friday to friday. So for the most part you have 3 games to get these minutes in.
Another thing, the three players you have on the Transfer list are nice, however for a center you want to alternate training Inside Shot, Inside Defense and rebounding, anything else is not gonna help your player as much. Its nice to have strong passing and strong handling as a center, however naturally centers aren't these types of players, and since they are so tall, these perimeter based skills train really slow, and stray away from your centers potential. Primary Skills also train slower if they are unbalanced, so try to alternate to keep it balanced and even. Good luck.