Wayne Rooney has dropped a transfer bombshell by telling manager David Moyes that he wants to quit Manchester United.And he will follow up his verbal demand by submitting a formal written request this week, prompting an improved £30million offer from Chelsea.Moyes hoped to persuade Rooney to stay at Old Trafford but, it is understood from club sources, the England striker has told him in face-to-face talks since he returned from their Far East tour last week that he is disillusioned with life at the club after nine seasons and wants a fresh challenge.Rooney, 28 in October, has ruled out a move abroad and is keen to join Jose Mourinho's Chelsea, who have been waiting in the wings for him to tell United he wants to leave before tabling an increased bid after their first £20m offer was rejected last month.United remain adamant they will not sell such a key player to one of their Premier League title rivals but Rooney's decision to put his transfer request in writing this week will change the dynamic of a saga that has been simmering for months.Rooney has assured Moyes he will continue to do his best for the club, but the fact he has admitted his head and heart are no longer with United gives the new manager a major headache with the new season less than a fortnight away.Moyes cannot sanction a sale and weaken his squad before he strengthens it and, as yet, his efforts to bring in Cesc Fabregas and Leighton Baines have not borne fruit.Rooney, it is understood, does not have a problem with Moyes but feels his position at the club has been undermined by Sir Alex Ferguson over the past 18 months.Rooney feels Ferguson forced the issue when he broke his trust by making public details of a private conversation they had in April. Now even if United belatedly make a public acknowledgement that Rooney did not ask for a move at the time, as Ferguson claimed after his final home game in charge in May, it will not change his desire to move on.The fact Ferguson, who personally recommended Moyes as his replacement, will continue to exert a huge influence at the club both as a football director and ambassador has hardened Rooney's resolve to leave.Comments from the club's chief executive Ed Woodward that United will not engage in new contract talks and are prepared to let his current deal run down have served only to increase Rooney's disillusionment.The England striker feels too much damage has been done and a fresh start is the best way forward. He played 45 minutes of a behind-closed-doors friendly against Real Betis on Saturday at the club's Carrington training ground and, according to insiders, looked fit and sharp in the 3-0 win having returned home early from the pre-season tour with a hamstring injury.Despite telling Moyes he wants to leave, Rooney will still be included in United's squad when they travel to Sweden today and is expected to make his first public pre-season appearance against AIK Stockholm tomorrow.Rooney knows he is likely to face a backlash from United fans when he makes his first Old Trafford appearance of the new season in Rio Ferdinand's testimonial game against Sevilla on Friday evening, but he will view it as added justification that his time at the club has come to an end.Moyes, meanwhile, has been given fresh hope in his pursuit of Fabregas after comments from Barcelona's new manager Gerardo Martino that a move back to the Premier League is up to the former Arsenal midfielder.Martino said: "I would prefer him to stay with us and I dare say he will, but it's his decision. "If it was my decision, there wouldn't be any chance of Cesc leaving."That appears to be a softening in the defiant "not-for-sale" stance Barcelona's hierarchy have adopted since United's initial £26m bid was revealed.