Pérez used a rare public appearance on Tuesday to claim Barcelona's payments to former referee committee vice-president José María Enríquez Negreira constituted the largest corruption case in football history, and suggested the payments had cost Real Madrid seven league titles over a 20-year period.
Yuste, speaking outside the team hotel in Vitoria ahead of Barcelona's game against Deportivo Alavés, did not hold back.
"Florentino's words struck me as pathetic and full of falsehoods. The club already issued a statement yesterday considering legal action, but I want to say that this manoeuvre by Florentino Pérez to cover up a sporting disaster that has been going on for two years will get him nowhere."
On the specific claim that seven leagues were stolen.
"Seven leagues stolen? This is a total falsehood. It is not like that, objectively speaking. He will know — but we are going to defend ourselves. We owe it to the fans and the club, and nobody touches this club."
He dismissed the entire episode as political theatre to distract from Madrid's on-pitch performance.
"It is not worth talking about Negreira again when we have won two leagues with a project based on La Masia players and others who have come from outside. We are winning it by 14 points and this is a smokescreen to try to justify poor sporting management."
Yuste also took aim at the timing and tone of Pérez's intervention.
"I watched the press conference afterwards, not live, and it did not make me laugh or cry. It gave me pity."
He confirmed Barcelona's legal department is actively reviewing Pérez's statements but offered no immediate timeline.
"There are no updates yet on possible legal action. The matter has been in the hands of the legal department since yesterday and when we have developments we will pass them on. But the red lines can never be crossed, and this man crossed them yesterday."
Yuste closed with a pointed note about the power shift at both institutions. Joan Laporta, who has been abroad in recent weeks, returns as Barcelona president on 1 July.
"I am going to say something to Señor Florentino. If you will allow me a little irony — on 1 July, Joan Laporta arrives, and there is a series in Spain called 'La que se avecina.' That says it all."
Pérez, 79, called presidential elections at his Tuesday press conference, though challengers face a significant barrier — candidates must have been Real Madrid members for 20 years and must provide bank guarantees equivalent to 15 per cent of the club's budget. He has run unopposed in the last four elections.