Messi, now 33, was set to earn a net salary of £50m in west London and was wooed by Mourinho in a video call.
In the midst of a tax evasion probe against Messi’s family in 2013, the Argentina international considered leaving Spain for pastures new.
And, according to Di Marzio, he was close to joining Chelsea.
Messi was keen on a move to London and had great admiration for Mourinho.
He spoke with ex-Chelsea star Deco – his former Barcelona team-mate who is now an agent – who promised him in a phone call that he can meet Roman Abrahmovich soon to discuss the terms.
Another intermediary, a friend of Messi’s, arranged a lunch date with Mourinho at his London home before the Portuguese spoke with Messi via a video call.
After Mourinho’s pitch to Messi, the six-time Ballon d’Or winner was said to be crazy about a move to Chelsea and the club set the wheels in motion for the mega-money deal.
However, there was to be a spanner in the works. New Chelsea arrival Cesc Fabregas spoke to Mourinho about the deal – delighted to hear that Messi would be joining him at Stamford Bridge – but questioned why he had not been answering Deco’s phone calls.
Furious at being cut out of the deal, Deco decided to snitch to Messi’s father, Jorge – who was not involved in negotiations up to this point.
Messi Sr. managed his son’s interests and questioned him over the deal.
Messi denied any knowledge of the deal to his father and the transfer collapsed.
He stayed at Barcelona and signed a new deal.