Thibaut Courtois wants Petr Cech, his rival for the Chelsea goalkeeper's jersey, to stay at the club.
Brazil goalkeeper Julio Cesar has joined Benfica on a two-year deal after being released by QPR.
Chinese side Guangzhou Fuli have confirmed an interest in signing Yakubu and hope to hold talks with the Blackburn striker at the weekend.
Yakubu hinted last month that he could leave Ewood Park following Rovers' relegation from the Premier League at the end of last season.
The Nigerian scored 17 goals in 30 league games for Rovers last term after signing from Everton and he has a further two years to run on his contract.
He was a target for Queens Park Rangers during the January transfer window, but could now be set for a lucrative move to the Far East.
Reports in China claim that Guangzhou have made Yakubu their top transfer target and are ready to offer the 29-year-old a contract worth £4.8million a season.
Guangzhou's deputy director Lu Yi told Jinghua Times: "Yakubu is our first choice and everything is going well now. We hope he will be in Guangzhou this weekend."
If the deal materialises, Yakubu will join a number of high-profile names who have moved to the Chinese Super League in recent times, including Paraguay international Lucas Barrios and former Chelsea striker Nicolas Anelka.
Didier Drogba is also expected to join the exodus to the Far East with the Ivorian tipped to link up with his former team-mate Anelka at Shanghai Shenhua.