Villas-Boas tasked with rejuvenating Chelsea

Owner Roman Abramovich has previously gone for the tried and tested in the shape of Jose Mourinho, Carlo Ancelotti and Guus Hiddink, all of whom lifted the continent's most prestigious club trophy, with World Cup winner Luiz Felipe Scolari also given a shot.

They all won domestic silverware but none managed to even reach the final of the Champions League, though Avram Grant did when Chelsea lost a penalty shoot-out to Manchester United in 2008.

The Russian billionaire has now changed tack and plumped for the potential shown by the 33-year-old Portuguese in leading Porto to a league and cup double and the Europa League title.

He did it with style too, his team raining goals during an unbeaten league campaign that produced 27 wins and three draws and a European run that included 17 goals for striker Falcao alone.

Abramovich may be reported to have been frustrated with the less-than-scintillating approach produced by some of his previous managers but Villas-Boas will win no favours by entertaining the fans en route to an early European exit.

The reason Abramovich felt able to pay the extraordinary 15 million euro fee to release Villas-Boas from his Porto contract is that he thinks he can take Chelsea up another level.

Mourinho did it after following the same route from Porto, where had defied the odds to win the Champions League, but despite taking Chelsea to back-to-back league titles, his failure to get beyond the semi-finals in Europe meant Abramovich was eventually happy to allow him to leave "by mutual consent."

On paper Villas-Boas inherits a squad that should not be too far away from mounting a strong European challenge but, beneath the glossy exterior, the plasterwork is anything but sound.

His first and most important task is to find a way of rejuvenating Fernando Torres so the Spaniard resembles the world-beating striker they thought they were getting when they paid Liverpool 50 million pounds for him rather than the surly, out-of-sorts benchwarmer they ended up with.

TOUGHER CHALLENGE

Ancelotti tried everything he could think of to accommodate Torres while trying not to upset the egos of Didier Drogba and Nicolas Anelka but none of his combinations produced the sort of effective attack that such a strike force should have done.

Villas-Boas is likely to try to persuade Colombia striker Falcao to follow him from Porto after his prolific season, though his arrival could trigger the departure of either Drogba or Anelka.

The tougher challenge for the new coach is to rebuild the team's midfield, or at least remodel its safety-first approach, which looked sluggish even by Premier League standards last season and was light years behind the pace and verve shown by European champions Barcelona.

Frank Lampard never really regained his best form last term after a long injury absence and the England midfielder, only a few months younger than his new boss, needs to impose himself again if he is to avoid the unthinkable of losing his place.

Michael Essien was similarly