Premier League - Reports: Fabregas signs for Barcelona
Catalan daily Sport claimed that the midfielder will travel to Barcelona on Sunday to undergo a medical after a five-year deal was agreed.
Barcelona meanwhile stated that "an announcement will be made in the next few hours", while Arsenal warned that it is not done yet.
There was no mention of a transfer fee, but Barca are thought to be paying up to £28 million with Fabregas's surrendered signing-on fee making up the difference to Arsenal's downgraded valuation of around £31m. Other reports have put the total figure at £35-36m.
Sport initially reported that he would be unveiled on Saturday and feature in the opening leg of the Spanish Supercopa against Real Madrid on Sunday, but then changed tack. If the deal does go through, he will not play in the Bernabeu but the return leg in Barcelona on Wednesday is a distinct possibility.
Fabregas has been the subject of one of the most protracted transfers in history. He was brought through the Catalan club's youth system before departing for Highbury at 16 years of age.
Now 24, he has long pined for a return to the Camp Nou - and delighted Barca stars Victor Valdes and Gerard Pique hinted this morning that a deal was about to go through.
"I think we have good news,'' goalkeeper Valdes told a news conference. ''Talks are very advanced. I cannot imagine Barca next season without Cesc. It is close. In a few hours they will announce his signing.''
Pique, who grew up playing in the Blaugrana youth teams alongside Fabregas, tweeted: ''Today is going to be a great day!!''
Arsenal are reportedly about to complete the £12m signing of attacking midfielder Jadson from Shakhtar Donetsk as a replacement for Fabregas.