The 34-year-old is now set to fly into the French capital later on Tuesday.
Barcelona announced on Thursday that Messi, who has spent 21 years at the club, will no longer be part of their set up.
He is now ready to take on a new challenge with the French Ligue 1 giants in a deal worth millions of euros.
Messi, according to the report, will sign a two-year contract – that includes a 12-month extension option beyond that point, on Tuesday.