Your player, if I don't make any mistake, is a 4* player for your team.
His value isn't a top one so I 'm not sure if he is very fast trainer.
A 4* fast trainer, must gain at least +130 in 3 bars, practice. What is his max gaining ?
Without any extra sources (greens & reds), the max he can get is to be a 5* player at the end of the season
so the next day (new season) he will be 4* player again.
Do you want to keep him as a 4* player

*If you have extra sources, with the new, no limit time, you can do training any time you want but I wouldn't spend my greens for a 4* player (maybe only for an exception, an T academy player who is superb performer).