Apparently Barcelona are willing to trigger his release clause too, but Rodri is a Atletico boyhood fan so I don't think he's willing to piss off his own club like that. If we fail to get Rodrigo (which seems quite unlikely at the moment), we could go for Thomas Partey who has a 50m release clause according to his agent.
He's been on Barcelona's radar before but I haven't read anything credible linking us to him recently. The AS article today only mentions that City are not the only club willing to trigger his release clause - the issue I see, potentially, is what Cerezo has said on the matter. He will not negotiate better terms with the player, if the player wants to go and a club willing to pay the clause then he's gone - in this case, Rodri would have to deposit the total clause like Neymar did
So if City/Txiki are willing to pay it and the player agrees to the project and wages, then it's done. Just a question of whether the player wants to leave and if so, if City & Pep are his preferred destination