Cech spent 10 years as Chelsea’s first-choice goalkeeper but completed a move across the capital on Monday after falling behind Thibaut Courtois in Mourinho’s selection.
The Portuguese would have preferred Cech to stay, rather than strengthen a rival, but respected Abramovich’s decision to allow a distinguished servant to choose his next destination and Cech chose to remain in London.
“I support the owner’s decision to honour the player in this way,” Mourinho said on chelseafc.com.
“Petr has been a great servant for Chelsea for 11 years and helped this club to win almost everything there is to win.
“I always said I wanted him to stay but I understand Petr needed to move on to play first team football every week.
“Sometimes you have to respect the wishes of someone who has earned so much respect with his service and actions for your club.
“It is very rare in football to make a decision like this and for that reason I am proud of my club for making it.
“There are not many clubs in the world big enough to be able to make that decision.
“Petr’s success at this club will always to be remembered and we thank him for everything he did.”