Chelsea have earmarked Manchester City's Joleon Lescott as an alternative if they fail to prise David Luiz from Benfica.
The Premier League champions are determined to bring in a centre half and have so far made bids of £17m and £21m plus Paulo Ferreira for 23-year-old Luiz yet Benfica insist they want at least £26m or the deal is off.
Manchester City offered a similar amount last season but still failed to land the Brazilian as Benfica demanded £35m and Chelsea are wary of being dragged into a saga should they match the demands.
However, owner Roman Abramovich has long been aware of the qualities Luiz could bring to his ailing squad and is eager to give it one last shot.
Carlo Ancelotti has drawn up a shortlist of five possible centre halves which is also understood to include Wolfsburg's Simon Kjaer, Bolton's Gary Cahill and Lazio's Stefan Radu.
However, left-sided Lescott fits the profile of what they want should a deal for Luiz fail.
Chelsea would only want to offer around £8.5million for the 28-year-old England international as they are wary of his knee problems.
City would want more for a player they spent £22m on barely 18 months ago but are keen to start recouping some hard cash for their fringe players.
Kjaer, 21, only moved to Wolfsburg last July for £11m but has had a difficult season.
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Explore more:People: Gary Cahill, Joleon Lescott, Roman Abramovich, Carlo Ancelotti Places: United Kingdom