The charismatic Portuguese locks horns with his old sparring partner Sir Alex Ferguson on Tuesday well aware that United have been in sparkling form of late.
While Serie A has not been at its strongest over the past few years, Inter's supremacy of one of Europe's top leagues is nonetheless impressive.
Mourinho, who guided Chelsea to two titles in his three full seasons at Stamford Bridge, anticipates an evenly fought battle over the two legs.
"I am actually pleased about that because my team plays better under pressure against the best teams," he told MUTV.
"We have always done well against Milan or Roma or Juve but sometimes against small teams we are not the same.
"We have to be at our best if we want to win the tie so I am happy to have such a big team."
Many pundits now believe he is the number one candidate to replace Ferguson when the Scot eventually calls time at Old Trafford.
Major challengeHe admits life in Italy is not the same as in England, although he does feel he is embarking on the biggest challenge of his entire career.
"I used to say the Premier League was more about heart and emotion," he said. "Serie A is more about brains and tactics.
"Every team in Italy is strong defensively. Every game is about tactics.
"It is not as beautiful as the Premier League. That is one of the reasons why the Premier League is loved around the world and Serie A is loved in Italy.
"It is more about the mentality and culture. But this is a really big challenge, the biggest of my career."