Maybe all but he has earnt it surely. He has earnt the right to have a say as well (if that is indeed what he is doing which some people are presuming is gospel truth)
What are your real concerns about this IF it were to happen?
Messi wouldnt have that player power here - the club is run by bigger people than him -Khaldoon for starters. He wouldnt have the power as depsite being the best player ever in the world he hasnt got the experience of the league nor the club to wield that power. He is the new boy. He wouldnt even be captain (Im presuming that will go to KDB this year)
A different surrounding might just be what he needs so he can get back to just playing football and not worrying about the politics of the club
I have no doubt Messi has enough left to be fucking brilliant, himself, for some years to come.
Watching him v Napoli, he sometimes received the ball in positions where the oppo were huge favourites to win it, but he was away & causing chances. Against Bayern, he threw the towel in, but his team mates were beyond a joke.
Will he beat two men & play that little pass through to Aguero, like Silva did ?
Well he doesn't, for Argentina, he beats a 3rd & shoots or loses the ball.
Barca is built around Messi but we are not. Ibrahimovic had to go, for Messi to thrive.
Will we drop him if he ruins the team structure, or start dropping everyone else ?
Will we have our identity or just be 'Messi' ?
Will Pep build a team, if we give him Messi, or will he just cash in, if it works, then fuck off ?
If Pep can't adapt to the tactics teams are now using v City & can't even build a defence out of Walker, Stones, Koulibaly, Aké, Laporte, Mendy, Fernandinho, thus proving he is finished at City, will he stay on because he's promised Messi, & go mental ? Will he leave & if so, what of Messi ? Will the next manager, try & fail, to build his team around Messi ? Can he ?
Etc.
It's not such a simple question as suggested