Ronald Koeman has admitted that he is "not confident" Lionel Messi will stay on at Barcelona beyond this season.
The six-time Ballon d'Or winner has spent his entire career at Camp Nou, racking up more than 750 appearances for the La Liga giants.
Messi failed in an attempt to leave the club last summer, but he is out of contract in four months' time and is able to open talks with foreign clubs regarding a free transfer.
Barca had been hopeful of persuading Messi to agree fresh terms, though Koeman cannot guarantee that the Argentina international will remain in Catalonia.
"I'm not confident about that," Koeman told The Athletic when asked if he thinks Messi will stay. "I'm hopeful, yes, because he's still a great player and he's still winning matches for us, for the team.
"I'm enjoying being his coach. If you look at his qualities every day in the training sessions, it's incredible. Of course, he came as a young kid to Barcelona. And I still don't see Leo Messi in another shirt other than the Barca shirt."
Paris Saint-Germain and Manchester City are considered the only two realistic destinations for Messi should he depart Barcelona in the summer.