The Premier League champions paid undisclosed fees to Sporting Lisbon for winger Nani, 20, and to Porto for 19-year-old midfielder Anderson, understood to be around $75million for the pair.

But in an interview with A Bola newspaper, Queiroz has accepted the pair will need time to bed into the English game and a foreign way of life.

He said: "Nani and Anderson are two young players who will start the integration work. I do not expect too many things from them this season. Instead, I expect sporadic contributions in different occasions in the season.

"[But] I expect their contributions could be crucial for our success."

Queiroz revealed the pair are unlikely to be regular first-team players while they acclimatise, although that could change in 12 months' time.

"They don't count for our team basic structure plan," he added. "They have to live an integration process: adaptation, preparation and evolution.

"If in 2008/09 season they are performing what we expect from them it will be very good."