The retired France international, who started his career in English football at Stamford Bridge with Chelsea, played under Mourinho from 2004 to 2006.
He later moved to Arsenal where Wenger was his manager from 2006 to 2010, but despite his two extra years in north London, preferred his time under the then Blues boss.
The 39-year-old spoke about the differences between the two legendary managers on Sky Sports’ Soccer AM and explained the reason for his preference.
“The difference is that both managers want to win trophies, but with Jose he will show you everyday at training,” said Gallas.
“If you are not 100 per cent he will stop training and say to you ‘what’s wrong with you, why are you not training?
“If you don’t want to train then just go outside and run, because what I want, what I expect from you is to give me everything in training and then you are ready for the game.'”
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“But with Arsene it is a little bit different. You have that responsibility to manage yourself, he won’t be behind you all the time.
“That makes a difference, so for me it was very good to be with one manager who was always behind you.”