Boss Paul Lambert today insisted Aston Villa and Liverpool have sent out a strong message to stamp out player power.
The claret and blues played hardball when Christian Benteke asked for a transfer before he performed a U-turn and signed a new deal.
Liverpool have stood firm over Luis Suarez’s pleas to quit the club and rejected bids from Arsenal.
Now Real Madrid are reportedly plotting a bid for the Uruguayan, who is back training with Liverpool but is suspended for today’s visit to Villa.
He is still banned for biting Branislav Ivanovic last season and Lambert said the clubs’ stance on their players lays down a marker.
He said: “The stance ourselves and maybe Brendan at Liverpool have shown is you still have a bit of power there.
“Players will eventually go, especially if they have been a brilliant servant and you say ‘on you go, you’ve got my blessing, good luck to you’. When it becomes difficult you have to draw a line under it.
“I know how hard it can be when you have something like that and have to try to turn it around. Sometimes you have to draw a line and say ‘no, you can’t go’.
“It’s tough because you have the players saying ‘what’s going on?’ and fans asking questions.”