Chelsea manager Andre Villas-Boas confirmed on Thursday that his club have made a bid for Porto defender Alvaro Pereira, but he doubts it will be possible to complete a deal for the Uruguayan.
Former Porto boss Villas-Boas is keen to be reunited with Pereira after their successful time together in Portugal last season, but the two clubs remain some way apart in their transfer negotiations.
"The only thing I can confirm to you is that we have made a bid for him and we are very far apart in terms of numbers," Villas-Boas said.
When asked if he was confident a deal could be done, he added: "Not very confident."
Pereira, 25, is regarded as an emerging talent after helping Uruguay win the Copa America and also playing a part in his country's run to the 2010 World Cup semi-finals.
If Chelsea were able to conclude a deal, Pereira would compete with Ashley Cole for the left-back berth and could also fill in at right-back.
Villas-Boas refused to be drawn on Chelsea's interest in Tottenham midfielder Luka Modric after the Blues reportedly made a £30 million offer for the Croatian last weekend.
Modric is desperate to join Chelsea but Spurs chairman Daniel Levy is refusing to sell and Villas-Boas said his next move was to speak to owner Roman Abramovich.
"I just have to speak to the owner (Roman Abramovich) when this kind of thing happens," Villas-Boas said.
"When there's an offer, there's a counter-offer and then you reach an agreement.
"Modric's name is already out too much in the press. Let's leave it. He's Harry Redknapp's player. He's not my player, unfortunately."
Villas-Boas can take comfort from the signing this week of Spain winger Juan Mata, who was lured from Valencia for around £23.5 million.
Mata is the first blockbuster deal of the Villas-Boas era and he joked: "Criticism was coming from all fronts at a lack of market activity, so you can lay off us now!"
Mata marked his arrival by admitting he hopes to bring the best out of Spain team-mate Fernando Torres, who has flopped following his £50 million switch to Chelsea from Liverpool in January.
But Villas-Boas added: "It's nothing to do with that. He's a fellow countryman (of Torres), but I don't even know if they get along or not."
Villas-Boas may be tempted to trim his squad following Mata's signing but insisted he had no intention of letting Florent Malouda leave after the France winger was linked with Juventus.
"As we are speaking about the number of goals and assists that Mata has made at Valencia, let's speak about the number that Malouda has made for Chelsea. We can't let ourselves sell talent of this quality," Villas-Boas said.