Clarke was grateful to Mourinho for the way he welcomed him into the fold during his first time in charge.
"I had it in the back of my mind that I would do it at some stage," he told the Daily Mail, "and I was at Chelsea - a club I loved with a job I loved, in charge of the youth team.
"Then Jose arrives. I'm presented with a choice. Do I stay as I am? Or take the risk to join him and his group, to work with a guy I didn't know and a group I didn't know?
"I knew I was the token Chelsea man. Sat there with my sweatshirt with the Chelsea badge on it and Chelsea scarf around my neck. It could have been a failure. I could have been kicked out with them. But that was the big step for me. I thought: 'Let's go and make a career of this'.
"They made me feel welcome. There were five Portuguese and me. If they did hold a conversation, one of them would always explain it, they made a big effort.
"As a coach, Jose was super-meticulous. Every session planned. I never went into a session not knowing what he wanted out of it. The players got the same messages.
"It was a great education. I was in charge of the youth team. Jose had just won the Champions League. I'm a quiet person. Suddenly, I'm working with a man who is super-confident.
"He changed the mindset of that club. Having said that, the team was growing. It had grown under Claudio (Ranieri)."
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