Mourinho, who joined Porto as coach five years ago, won the UEFA Cup and a domestic double in his first season before retaining the league title and winning the Champions League with a 3-0 victory over Monaco in Gelsenkirchen the following year.

The Chelsea boss recently claimed he was the best manager to emerge from Portugal but Ferreira insists only the future will determine whether he is right or not.

Ferreira said: "Jose Mourinho has been a manager for five or six years and it is unquestionable that he has had great success.

"But there are still some years ahead during which time that status might be confirmed."

Porto have a difficult task on their hands if they are to progress to the last eight of the Champions League at Chelsea's expense.

Andriy Shevchenko's equaliser for the English champions in Porto a fortnight ago earned Mourinho's side a vital away goal in a 1-1 draw.

Ferreira says he will make changes to his line-up tomorrow night but would not reveal whether he will stick with former Chelsea transfer target Adriano in attack.

Porto remained top of the Portuguese league by overcoming Braga 1-0 last weekend with Adriano, preferred to top scorer Helder Postiga, notching the matchwinner in the ninth minute.

Chelsea's home advantage should be enough to see them overcome the Dragons, even though the visitors have conceded just 10 goals in their domestic league so far this season.

But Ferreira is without the services of defender Bosingwa who damaged a thigh in the win over Braga.

He has not travelled with the squad but Argentina midfielder Lucho Gonzalez, who was taken off in the same match with a minor injury, is fit for selection.

Chelsea have not lost at home since Mourinho took charge in the summer of 2004 but Ferreira does not see that as a major obstacle in their quest to defeat the English champions.

Ferreira said: "The Porto team will be different and it will have to be more sure of itself.

"The fact that Chelsea have not lost at home does not, in itself, mean anything. That is not the strength of the team - we have to play well but being unbeaten at home is not necessarily the thing that determines the outcome of a match.

"We are playing a very strong team and we are a team that wants to be strong as well. It is difficult to measure these things but I am sure we have the means and we are capable of coming through this qualifying round."