Chelsea have had a £22m bid for Valencia winger Juan Mata rejected by the La Liga club.
The Blues made a move for the Spanish international, who is also a target of Arsenal, as Chelsea manager Andre Villas-Boas looks to add width to his squad.
However, Chelsea's bid, comprising £18m up front and £4m at a later date, has been turned down.
Chelsea may yet make an improved offer of £26m for Mata, who is reportedly keen on a move to Stamford Bridge.
Arsenal still have a bid for the 23-year-old on the table, although they cannot yet guarantee Champions League football next season.
Meanwhile, Chelsea will still continue their pursuit of Tottenham's Luka Modric as Villas-Boas is expected to let Yossi Benayoun move on before the end of the transfer window on Wednesday, August 31.
Chelsea continue their Premier League campaign with a home match against West Bromwich Albion on Saturday.