The 36-year-old has not been impressed with the Chelsea-bound Portuguese coach's behaviour at the Bernabeu after what he described as his "worst season" in football
Los Blancos saw arch-rivals Barcelona win the Liga title, while they were beaten by Atletico Madrid in the Copa del Rey final and were eliminated from the Champions League in the semi-finals at the hands of Borussia Dortmund.
Those defeats proved to the final straw for the 'Special One', leading to Mourinho's departure at the end of the season.
"When you've had your worst season, showing a bit more humility would have done us all a favour," Guti told Marca.
" We expected big things from Mourinho and not just in terms of trophies. It's been a let-down for all Madrid fans. That's the way we see it, anyway.
"I haven't been there to see what's been going on in the dressing room day after day, but if you have a four-year contract and then you want to leave as soon as you have an average or bad season, I think it's fair to say he's jumped ship.
"The most recent comments from Pepe, Cristiano [Ronaldo] and Iker [Casillas] do give the impression that the situation had become untenable. Maybe he thought that leaving would be in Real Madrid's best interests."
Mourinho guided Madrid to one Liga title, one Copa del Rey trophy and the Spanish Supercopa during his three-year spell in charge at the Santiago Bernabeu.