Pep Guardiola warned Barcelona president Josep Maria Bartomeu not to "talk too loud" about Manchester City's European ban after the Catalan club's chief welcomed UEFA's action.
City were banned from European football for two years by the game's continental governing body on Friday following historic Financial Fair Play breaches.
The reigning Premier League champions have appealed the decision, and will take the case forward to the Court of Arbitration for Sport in the coming months.
Barca chief Bartomeu praised UEFA for looking into the City case and taking action earlier this week.
“I would like to thank UEFA regarding FFP,” he said, via Fox Sports.
“They’ve been doing fantastic work in the last couple of years. We have regular investigations and we have supported UEFA in everything it does in football.”
Those comments didn't go down well with Guardiola, who won the Champions League twice while manager of Barca between 2008 and 2012, adding three La Liga titles and the Copa del Rey twice.
“I don’t know if they spy on me but they know me, it’s not necessary to spy on me," said the City boss at his press conference after his side's 2-0 win over West Ham in the Premier League on Wednesday evening.
“If they are happy we are suspended, I say to the president of Barcelona, let us appeal.
“The people [at City] right now trust what they have done so that is what we are going to do. We’re going to appeal and maybe it happens but don’t talk too loud Barcelona.
“That is my advice because everybody is involved sometimes in situations. We are going to appeal and hopefully in the future we can play in the Champions League against Barcelona.”
