According to the Daily Mail, Blues coach Andre Villas-Boas has told Roman Abramovich he needs to inject more flair into his side and the billionaire Chelsea owner has responded by making £60million available for new players.
Chelsea reportedly had a £22million bid for Mata rejected by Valencia this week and the newspaper claims the Barclays Premier League club will now return with an offer of £27million, plus £2million in top-up payments.
Mata's stock has been on the rise and Chelsea's Premier League rival Arsenal were also understood to be monitoring the winger who starred for Spain at this summer's European Under 21 Championship.
Additionally, sources close to the Daily Mail indicate that Villas-Boas will attempt to wrap up the signing of Tottenham star Modric before the transfer window shuts in less than two weeks time.
Spurs had previously rejected a £27million offer from the Blues for their Croatia international midfielder but coach Harry Redknapp recently admitted that a fresh injection of funds could help him improve his squad.
Spurs chairman Daniel Levy remains the main obstacle - his stance on Modric not being available at any price has not softened.
Chelsea have stood watch this summer as title rivals Manchester City and Manchester United spent more than £50million on new players while the Blues only major transaction in the transfer window so far was completed on Thursday with the £20million signing of Romelu Lukaku.
Chelsea have high hopes for Lukaku, who has already been backed by Villas-Boas to become as big a Stamford Bridge legend as Didier Drogba.