Cesc Fabregas will return to Arsenal on Monday to undergo fitness tests ahead of the start of pre-season training, according to the Daily Telegraph.Many had expected Fabregas to have signed for European champions and boyhood club Barcelona by now, but with the two clubs still unable to agree on a fee, the World Cup winner remains an Arsenal player, and will go through tests before the Gunners begin pre-season on Tuesday.The Catalan giants are said to have tabled an improved bid of around €35 million for the Arsenal captain, but the Gunners are holding out for more.However, there may be a further contributing factor in the story as Arsene Wenger secured the signings of Barcelona’s Jon Toral and Hector Bellerin earlier in the summer, with both 16-year-olds having rejected contracts at Camp Nou.Barcelona are said to be outraged by Arsenal’s actions, and are threatening to report the London club to Fifa, making a claim of £350,000 for each player.However, Barca have apparently said they will withdraw the claims if Fabregas is their player come the beginning of the season.Arsenal, who travel to Kuala Lumpur for their Far East tour next weekend, believe they have done nothing wrong and look determined not to let their captain leave for less than they believe he is worth.Meanwhile, Catalan newspaper Sport has claimed Fabregas will not train alongside his team-mates or play in any of Arsenal's pre-season games as he looks to seal his dream move to Barcelona.Sport also claim Barca coach Pep Guardiola will adopt a 3-4-3 formation to accommodate Fabregas in a midfield diamond.Back at Arsenal, Wenger is said to be meeting Samir Nasri on Monday in a last-ditch effort to try and convince him to stay at the club.Interest is high in Nasri, with both Manchester clubs chasing the Frenchman’s signatureSource: Goal.com