Panucci reckons that Ronaldo is currently on another planet and says the Roma defence will keep a close eye on the Portuguese.
"Cristiano Ronaldo is a genius and our plan is to try and make life uncomfortable for him on the pitch," he told the channel. “Manchester United are less threatening if the Portuguese is marked.
“We are preparing for the encounter in a very calm state of mind because the pressure is on the English. In the last round Real Madrid were favourites and we rose to the challenge."
United hammered Roma 7-1 last season, but Panucci claims that game has been erased from the memory banks.
“Roma don"t fear United," Panucci said. “It"s about XI men against XI men on the pitch and we have as many chances to qualify as them.
“These days we play the best football in Italy and the English will suffer in Rome. We expect to play 180 minutes to the death.
"At the moment Manchester United are the best team in England but it"s a different story in the Champions League because all the games are different.
“The knockout will be decided at Old Trafford and we need to make the trip to England with the maximum chances to qualify.
“It means that we need to achieve a perfect match at home and keep a clean sheet."
Both clubs have called for calm following recent clashes between fans and Panucci wants a friendly atmosphere in the stands.
“I don"t doubt the stadium"s atmosphere will be spectacular," he commented. “Roma"s fans need to give a lesson of perfect behaviour, following the past experiences."
Francesco Totti is out of the first leg and Panucci reckons it is a big blow for the home side.
“Totti"s injury is bad news because he has been sensational for us, like during the games with Real Madrid," he declared. “Our defenders are prepared for a tough battle against Man United"s attack as every footballer dreams to play such games."
The former Monaco player remembers the unforgettable 7-1 defeat at Old Trafford and claims it will never happen again.
"Last year"s 7-1 is history and it"s impossible to repeat such a display," he said. “For sure it was a terrible moment for Roma, but we are not obsessed by it."