Terry and Mourinho built a close relationship before the 50-year-old left in 2007 but the club captain says he will not be given any special treatment.
"He's still as passionate as he always was," said Terry.
"People have said that he's a lot calmer but I don't see that at all. I see a man who wants to win every day.
"Regardless of what we've done before it's back to square one and a clean slate for everyone.
"He made that clear with myself and other players and that was important for me because we did have some great times before but he said to me that he's here to win and he'll pick the best team that he sees fit.
"There's no guarantees that you'll be in the side, nothing, whether you're captain or not. He made that very clear from day one."
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