Speaking to Cadena Ser, Courtois wished Bale all the best - but couldn't resist a cheeky swipe at his new club.
"What one says to the coach is personal," former Chelsea keeper Courtois said with reference to Bale's up-and-down relationship with Madrid manager Zinedine Zidane.
"I don't know what he thought, but then they are decisions that each one makes.
"I've had a good relationship with Gareth and I wish him the best of luck this year, even if he's not playing for the good team in London. Gareth is a great player."