it isnt too late you do fridays training then sack him, this will save you 60k
next week after your home game you will have enough to hire a level 4, maybe sell a player you don't need if you are really tight for cash
if you want to save even more then stick with the level 1 you get after sacking the old level 6 and just do stamina or ft training for a week, by then you should be fine