The Red Devils, having lost out to Bayern Munich in their pursuit of Thiago, have now turned their attentions to the former Arsenal man and have tempted the Catalans with a €30-million bid.
Arsenal have a massive transfer kitty this summer, but have so far been unable to lure any big names to the Emirates Stadium.
However, Barca believe that the 26-year-old is worth more than that and will shortly inform their English counterparts of their viewpoint, according to Sky Sports News.
The report added that while Fabregas has no intention of forcing through a move, he is open to the prospect of a return to the Premier League.
Arsenal are believed to have the option to buy the Spanish international back for £25m as part of the deal that took him to Camp Nou in 2011.