The former Arsenal player signed for the Catalan giants in 2012 for a fee in the region of 16million to provide cover for both the defensive midfield and centre-back position.Despite his hefty fee, the 26-year-old has proven to be unreliable when called upon and sporting director Andoni Zubizarreta is looking to find a new club for the player.With Manchester United known to be in the market for a defensive midfielder and having enquired about the player in the past, Barcelona are set to offer him to last year’s champions at a around ˆ10million (8million) to recuperate at least half of the fee they paid Arsenal.After a disappointing Premier League campaign, United will be in the market for a midfield enforcer and were said to have been interested in Song last summer but Barcelona were not prepared to sell.However, with the club looking to make a summer clearout, a cut-price for a midfielder with Premier League experience could be a viable option.