Mendy looks up to the Whites head coach, having credited Bielsa for 'waking him up' during the season they spent together at Marseille.
"From the day he arrived in Marseilles, I learned why they called him El Loco," he told The Players' Tribune.
"He was very professional, very serious. When he addressed the players the first time, he didn't smile once. But when he talked about strategy, you could see the madness coming out. You could see his passion. You could see that he lived for football, for every detail. After the meeting, a teammate looked at me and said, 'He is not normal, this one!' He was right. Bielsa is not normal. Who wants normal?
"I learned a lot from him by focusing on what others might say is 'boring'. That is how Bielsa thinks about football: What if boring is where you gain the most advantage?
"When he arrived, I was lazy about watching video.
"I didn't take it seriously. I would fall asleep during video sessions. When I would open my eyes, Bielsa was still there, with the same serious look on his face, and he would say something like, 'I am waiting for you to be interested'. With his help, I learned how to watch video for the details. I became very interested in video and tactics. That was his effect on me. I always tell people: Bielsa woke me up.
"And if you ask Marseille supporters, I think they would say that he woke them up, too. They are people who respect what is simple — working hard and doing your best. They are not arrogant or flashy. Bielsa was a famous man but he could walk the streets without being bothered. Everybody felt like he was part of the Marseilles family."