Why Fab can't leave Barcelona

Despite the inevitable desperate pleas from Manchester United manager David Moyes, new Barcelona manager Gerardo Martino must resist selling Cesc Fabregas to the Premier League power. 

According to BBC Sport, the new head man at Old Trafford remains hopeful that he will be able to lure the La Liga side into selling the 26-year-old midfielder. He called the negotiations "ongoing" despite two failed bids for the star already.
The latest offer, one that was swiftly turned down by Barcelona, was worth £30 million, plus add-ons, per BBC's report. 
Ben Smith of BBC reported earlier in the week that the offer was expected to be turned down because Fabregas is not on the market. For the sake of Barca fans, they had better hope that the words from the organization are the actual truth and not a ploy to garner more money for the 26-year-old. 
There's a reason that United would love nothing more than to pry Fabregas away. He would instantly give them a star in the midfield that would once again give them the most powerful lineup in the league. 
However, he's an asset that Martino can't afford to part ways with. Since joining Barca, he's been an underrated key to their success there's an appreciable difference in results depending on him being on the field. 

While most of his appearances for the club have been as a midfielder, dishing out assists to Messi and the rest of the frontline, he made 10 appearances as a forward last season. 
In those 10 appearances he scored five of his 12 total goals on the season and three of his 12 assists. Considering his limited time at the position those are impressive numbers. 
The attack in Barcelona may be all about Lionel Messi. He is the most prolific goal scorer in the world and all, but it's good that the club can be assured they have a capable back-up plan should Messi be forced to miss time next season. 
United is bound to escalate their bid for Fabregas as the club gets more desperate to make a summer splash, but Barca must stand strong and realize they won't find many players with Fabregas' ability to both score and distribute while playing both positions.