Information gathered revealed that Messi will train personally, due to the La Liga strict Coronavirus protocols before reintegrating with his teammates at a later date.
The La Liga giant will host Gimnastic in a friendly at the Johan Cruyff Stadium on Saturday, but Messi is not likely to be involved.
He could feature against Girona in another friendly on Sept. 16 ahead of the season opener against Villarreal at the end of the month.
Messi had earlier revealed his desire to leave the club.
Messi accepted defeat on Friday, though, telling Goal he would not take the legal route to force a Camp Nou exit.
It is the first time he’s been face-to-face with Koeman since the two held a meeting on Aug. 21. In the meeting, Messi told the Dutch coach of his desire to leave the club.