Barcelona claim they will complete the signing of Portugal's playmaker Deco by the end of the week.
Deco seems destined to leave European champions Porto
The Catalans will pay Deco's club Porto £8.04m but are meeting resistance in an attempt to throw winger Ricardo Quaresma in as a makeweight.
Barca president Juan Laporta said: "We only have to tie up the final details of the agreement.
"I'm quite optimistic and believe that Deco will end up becoming a Barcelona player."
Chelsea were favourites to sign the Brazilian-born star after the arrival of his former coach Jose Mourinho at Stamford Bridge.
But they appear to have pulled out of the race to sign Deco, who seems certain to leave Champions League winners Porto, leaving bitter rivals Barcelona and Real to fight for his signature.
A Porto spokesman told BBC Sport earlier this month: "There is no agreement with Chelsea to sign Deco. Our President has also told me Real Madrid are interested in Deco.
"There is also a chance that Deco will stay with us next season."
Deco scored the second goal in Porto's 3-0 win over Monaco in the Champions League final in May.
The midfielder has been a key member of Portugal's squad since he acquired Portuguese citizenship in March 2003.