The gifted Argentina Lionel Messi is a target, but the Blues do not believe he would leave Barcelona. Instead, they are more focused on Bayern Munich's Franck Ribery and Real Madrid defender Sergio Ramos.

Right-back has long been a problem position. Juliano Belletti is considered good going forward, but liable to be caught out defensively, while Paulo Ferreira is seen as a back-up player.

With the possibility that Ricardo Carvalho could quit the club to join up with former Chelsea coach Jose Mourinho when he ends his exile from the game, the Blues are desperate for more quality at the back.

Ramos, who began his career at Sevilla, became the third-most expensive teenager in history when he moved to Real in 2005 for around £20 million (S$54 million), signing an eight-year contract, reported the Guardian.

Although he started off in the middle of defence, he has since established himself at right-back.

He impressed both as an attacking threat and defensively to such an extent that the AC Milan veteran, Paolo Maldini, recently suggested Ramos was fast developing into 'the best defender in the world'.

Madrid chairman Ramon Calderon yesterday insisted any bid from Chelsea for Ramos will fall on deaf ears.

'Ramos' future is in Madrid,' he said. 'He could only leave if he wanted to, but I do not see any sign. He is happy with us.

'Who is happy at Real Madrid will want to move to another club?'

However, Real's reluctance to increase his pay with a new deal, while handing out contracts 'for life' to the likes of Iker Casillas, Guti and Raul, has prompted some resentment in Ramos' camp.

Reports emanating from Spain claimed a deal worth in excess of £50 million had already been struck for Ramos.

Sevilla's Daniel Alves, Inter Milan's Maicon Douglas, and the right-footed Bayern Munich defender Philipp Lahm are seen as the other options.

Another problem position that has been identified by coach Avram Grant and sporting director Frank Arnesen is that of left- wing, especially given the uncertainty surrounding Florent Malouda's future.

Ribery, the livewire Frenchman who tore England apart in Paris on March 26, has been tipped as a potential option. This, despite signing just last year for a club-record 25 million euros (S$53.5 million).

He led Bayern to the German title last week.

Whether Chelsea sign a striker or not will depend on Didier Drogba's decision to leave.

Valencia's Spanish international, David Villa, has been mentioned. Grant has also been impressed by Stuttgart's Mario Gomez, who is second in the Bundesliga scoring chart this season with 18 goals and will cost some £27 million.

A summer clear-out of fringe players is inevitable. As well as Cudicini and Belletti, Shaun Wright-Phillips, Steve Sidwell, Claudio Pizarro, Tal Ben Haim and Andriy Shevchenko are also likely to pack their bags.

One player who may not leave is Barcelona target Frank Lampard, reported the Telegraph.

He has been moved by the concern shown towards him by both staff and fans, following the death of his mother.