The Portuguese tactician was heard during a conversation about his lack of firepower at Stamford Bridge claiming that 32-year-old frontman Eto'o could be as old as 35.
The Cameroonian striker was offered the opportunity to reply following a UEFA Champions League outing at Galatasaray on Wednesday.
Eto'o was happy to joke about the issue with reporters, claiming he still has 'juice' and can keep scoring goals 'until I am 50'.
He went on to explain to beINSports that while he was disappointed not to start Chelsea's latest European outing, he has no axe to grind with his boss and will not be drawn into a debate regarding a discussion which Mourinho considered to be private.
Eto'o said: "I am Samuel Eto'o, to disturb me will take much more than this. I know my place and I won't reply.
"I would have liked to be in the starting XI so I am disappointed to be on the bench, but I respect the choice of the coach.
"I came to Chelsea mainly because of Jose, because we have a great friendship.
"Things happen in life and you have to face them. But it doesn't change the player I am and the career I have had.
"You want me to cause trouble by revealing all of my thoughts. I want us to go as far as possible in this competition and in peace."