The report claims that officials at the Camp Nou believe that both clubs are best placed to sign the Argentine star because of their financial muscle and their current squads.
The 33-year-old has a clause in his deal allowing him to leave at the end of any season, and whilst it was thought that deadline passed in June, Marca say his camp believe that it has been extended in line with the prolonged 2019/20 season.
However, this report states even if Messi cannot exit on a free, he would be sold in an “affordable” fee which could be topped at €100m, even though there is a reported €700m release clause in place.
PSG would be well placed due to their financial muscle and Neymar – a close friend of Messi’s – being a star, while United are hopeful of renovating their squad this summer.
Inter are another club who are mentioned in the report, but despite their financial muscle, the Blaugrana do not envisage an approach from the Italian club.
That follows on from a Deportes Cuatro report earlier on Tuesday that claimed United were in the driving seat to sign Messi.
It comes as the Association Press report that the Catalan giants contacted them directly on Tuesday to confirm that they have received documentation from the Argentine that he intends to quit the club immediately.
It confirms the multiple reports across Spanish and Argentinean media which claimed that Messi intends to leave Barcelona and will attempt to activate a clause in his deal which allows him to break his contract.
Messi has won a record six Ballon d’Or awards during his spell at the Camp Nou, where he has spent the entirety of his professional career and firmly established himself as one of the greatest footballers ever to play the sport.
Messi has scored a scarcely believable 634 goals in 731 official appearances for Barcelona, but his time at the club now appears to be up and he is hopeful of becoming a free agent.
The Blaugrana confirmed the arrival of Koeman on a two-year contract last week following on from the Barcelona news which had centred on the replacement for Quique Setien, who was sacked as Barcelona boss on Monday after just seven months in the role.