The Stamford Bridge outfit knocked Stoke City out of the competition with a 1-0 victory on Sunday thanks to a fabulous Oscar free-kick, and discovered their fifth round fate in the subsequent draw.
But Mourinho stressed his side would not be daunted by a trip to the Etihad Stadium in the last 16, just a couple of weeks after playing them in the Premier League.
"Our priority is to improve and the best way to improve is play against Man City twice in 15 days away from home," he said.
"We are ready to go to City and enjoy it. We will go there with a good attitude and we have nothing to lose."
Chelsea looked comfortable throughout, and Mourinho expressed his disappointment that his side failed to put the game to bed after going ahead in the 28th minute.
"We played a very good game, the scoreline doesn't reflect the dominance of our game," he continued. "We had some fantastic individual actions and very good collective movements. The free-kick made us happy.
"We hit the post twice and Begovic showed how good he is. In the last 10 minutes everything was open but we controlled it."
Nemanja Matic made his first start since returning to the club from Benfica earlier this month, and Mourinho was full of praise for the midfielder's performance.
"Matic did very well," he added. "He was very comfortable, stole lots of balls and his passing was quality.
"He's very comfortable on the ball, his left foot is sweet and he makes things simple, which lets the team fly."
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