Porto coach Vitor Pereira has jumped to the defence of Chelsea boss Andre Villas-Boas.
Pereira, who was Villas-Boas' assistant during Porto's record-breaking quadruple-winning season last year, is currently preparing his side for Thursday night's Europa League last-32 first leg against Manchester City.
Pereira said: "Andre is a quality coach and will certainly, in time, prove his quality and competence."