Carlos Queiroz has warned Cristiano Ronaldo about potential pitfalls off the pitch as he looks set for a switch to Real Madrid.

The Portugal coach was once in charge of the backroom staff at the Bernabeu and he understands the culture at the club.

As such, the former Manchester United assistant manager wants Ronaldo to stay focused on football should he complete his £80 million switch from Manchester United to Real Madrid.

The 56-year-old knows the Spanish capital well from his time as head coach of Los Merengues during the 2003/04 campaign.

The former Red Devils assistant-manager is confident that the 24-year-old will flourish at the Santiago Bernabeu, provided he does not succumb to the bright lights of the Spanish capital.

"I have my opinion about my wish regarding the career of Cristiano - and I think Manchester United was the right club for him," Queiroz is quoted as saying by The Sun.

"It's something to do with the fashion, the television, a different game that is in place nowadays.

"I must say that at Real Madrid, these things can happen very easily."

Queiroz also believes that other off-field responsibilities, such as marketing and sponsorship, could also have a negative effect on Ronaldo's career if he does not keep them in check.

It is claimed that the last Galacticos era failed to sustain a dominance because players were bombarded with the aforementioned commitments.

"I'm sure that since a few years ago, [club president] Florentino [Perez] and his aide Jorge Valdano will have learned from their mistakes," Queiroz remarked.

"Then the players were too committed to advertising. There were a lot of compromises and deals away from the pitch.

"When the club is huge and you put together players like Figo, Zidane and Roberto Carlos, the challenge is huge.

"With Kaka and Ronaldo, that's something they will come up against. But I'm sure the club have learned from the past."