Porto chairman Jorge Nuno Pinto da Costa believes Andre Villas-Boas' decision to leave the Estadio do Dragao for Stamford Bridge last summer was a 'mistake'.
Villas-Boas led Porto to unprecedented success last season, but has failed to transfer his philosophy since moving to Chelsea in June of last year.
Following a limp defeat against Everton on Saturday, the Blues are now fifth in the Premier League and appear to be in danger of failing to qualify for next season's Champions League.
Add to that reports of player unrest and, what appeared to be a dream job for Villas-Boas, is quickly unravelling.
Pinto da Costa feels the 34-year-old was too hasty when he accepted Chelsea's offer last year, and should have continued his development in Portugal.
"He left thinking that Chelsea was a unique opportunity, but I believe that was a mistake because there would have been others.
He added: "He needs time to mould his own team and he can't do that as long as there are players, as I've heard, who exchange text messages with Mourinho, and (Roman) Abramovich knows this."
Pinto da Costa does, however, expect Villas-Boas to retain his position at the Chelsea helm for next season, unless the Blues fail to secure a spot in the Champions League.
And, should Roman Abramovich decide to fire Villas-Boas, Pinto da Costa has tipped him to succeed Claudio Ranieri at Inter Milan.
"The only thing that will topple Villas-Boas is if he fails to qualify for the Champions League," Pinto da Costa said.
"If he leaves Chelsea, he'll be the next coach of Inter."