If anyone had said that Cristiano Ronaldo would be leaving Real Madrid after the forward helped the club win the Spanish League and the UEFA Champions League this season, then his sanity would have been brought into question. However, yesterday's bombshell news that Ronaldo has made his mind up about leaving the Spanish champions has made the top European sit up and take notice. None more so than his former club Manchester United.

A bolt from the blue

When the news first broke in Portuguese media that Ronaldo had made an 'irreversible' decision to quit Real Madrid this summer, there was widespread disbelief and many did not quite take the story seriously.

However, as the story developed, it became clear that the current holder of the Ballon d'Or had definitely made his mind up about leaving the club which he had served for 8 seasons.

Naturally, it is now almost certain that some of the biggest clubs in Europe will now be calling up his agent to see if a deal could be done. Ronaldo's astronomical wage and transfer fee rule out most clubs in Europe except the so-called 'super clubs'. Among those, his former club Manchester United is definitely one of the viable options for the Portuguese star as he looks for a new club which can match his ambitions.

Can it happen?

Cristiano Ronaldo making a fairytale return to the club where he made his name might have seemed far-fetched a few months ago but now it is a genuine possibility.

Ronaldo is apparently outraged at the allegations of tax fraud and feels that he has had enough of Spain. The world's highest-earning athlete would, however, need a club which can foot his enormous salary.

Manchester United recorded a revenue of around $739 million (converted from 577 million GBP) and in addition to that, they are apparently prepared to do all they can in order to bring back their former star to Old Trafford.

Ronaldo's $512,000 per week wage (converted from 400,000 GBP) would also not be a problem for the club and additionally, they have already offloaded Zlatan Ibrahimovic, who earned massive wages.

However, United are surely going to be a bit circumspect before they go all in for him due to what happened back in 2013. That year, Ronaldo was almost certain to leave Real for United but eventually decided to sign a mega deal and stayed put.

The club cannot afford to be played like that once again and must place a bid only if they have reassurances that this time Ronaldo is definitely going to leave. Other than United, French club Paris Saint-Germain is also interested in the player and have the financial clout to match any offers. However, United is almost certain to be Ronaldo's first choice if he quits Real Madrid.