You know you can just let a player play for a whole game to give him maximum training minutes of 48+ minutes although it is filled with the risk of being foul out and injury but it may works. Its easy if you're only training one player, if using my above tactic, try let him play for the saturday game which is the first training game after training update and see if he is fouled out or injured, if fouled out you can always let him play as a back-up for the 2nd training game, if injured, thats your luck, but I think a high level doctor can reduce their injury period down to only injured for the match.
Just my opinion.