Former Real Madrid captain Guti is fed up with Gerard Pique's off-field antics, slamming the outspoken Barcelona defender for unprofessional behaviour on social media.
Pique and Madrid full-back Alvaro Arbeloa have played out a public spat for much of the season and the feud reigned following Barca's 1-0 defeat to Real Sociedad last week.
After Arbeloa commented on Barca's surprise loss on Twitter, Pique mocked the 33-year-old's role at Madrid, insisting "a player who has started once in 32 games doesn't deserve a response".
Guti has watched the Twitter war play out and the three-time Champions League winner said he is stunned by Pique's lack of respect for his counterparts.
"You're the funniest man on the planet whenever Madrid lose but when Barca slip up, what, no one can tweet about it?" Guti said on Spanish television show El Chiringuito de Jugones.
"You have to be a man and accept those tweets when you're beaten. He's gone too far too many times. The whole Pique thing is outrageous. I've never seen another active Madrid or Barca player disrespect a fellow professional like he has.
"I've had enough of Pique's behaviour. He can't get away with talking about Arbeloa the way he has. Barcelona should make an example of him."
Guti added: "It's one thing for him to be happy that Madrid lose - I feel the same way when Barcelona lose - but it's another thing to slag off a fellow professional.
"He hasn't learned anything from Xavi and [Carles] Puyol. His personality is beginning to overshadow his footballing ability. How long have we been talking about Pique's off-the-field antics? He has been grabbing the headlines all year because of his extracurricular activities."