We will have to wait to see Leo Messi in action. The idea is for him to return on Monday 2nd August to start the week together with Emerson and Sergio Aguero who have yet to return to the club. However, he will not do so until he has signed his new contract at Barcelona.
Since 30th June, Messi is a free agent. He does not have a team officially although it is well know that he has been negotiating his new deal with Barcelona for a while.
Barca are working on possible departures to reduce the wage bill. The aim is none other that be able than to register Messi and still stick to the FFP rules.
And until Messi signs his new contract, 'Mundo Deportivo' says that he will not train together with the rest of his teammates. The club are not thinking of that and neither is Messi.
Until Barca make a formal offer and Messi signs it, there will be no sign of the '10' in Barcelona's side. We will therefore have to wait, therefore, to see the Argentinian training under Koeman.
The latest to talk about Messi's new deal was LaLiga president Javier Tebas, "It all depends on Barca, they know the rules," he said. LaLiga have made it clear that they will not make exceptions and they will review everything in detail to make sure Barça stick to the rules.