The former Arsenal and Chelsea defender has played under both bosses at the London giants.
Mourinho and Wenger appear to be permanently at war with each other - and they're different on the training ground as well.
The Frenchman has explained how both have different styles when it comes to drilling their troops.
Gallas told Soccer AM: "Both managers want to win trophies but with Jose he will show you every day at training [what needs to be done].
"If you are not 100% he will stop the training and say to you 'what's wrong with you? Why don't you train?
"If you don't want to train just go outside and run, because what I want and what I expect from you is to give me everything'.
"And with Arsene it's a little bit different.
"You have to be more responsible to manage yourself so he won't be behind you all the time and that makes a difference.
"So for me it was very good to be with one manager who was always behind me."
