He can stay, his contract allows that liberty, however he should be dropped and used sparingly without the 60% clause getting close to being triggered. He's bound to sulk heavily at first, you just need to see how he reacted when he scored off the bench to see that, but needs to realise his time is up. Not like he's being forced out at 29 or 30, he is 33 but physically shot at the top level.
His friendship with Messi has allowed him a false sense of entitlement, and if hadn't spent the majority of the last two years being more detrimental to the attack instead of contributing I'd understand why he'd be miffed. His stats without context look decent, but he has become a burden now and a name that can't be dropped. Barca needs to become a team again instead of individual names picked through hierarchy.