Mourinho was unwittingly caught on camera lamenting the quality of the strikers at his disposal at a sponsors' event in Switzerland in February, and suggested that Eto'o could be older than he claims to be.
The now-33-year-old appeared to react in jest by celebrating his next Chelsea goal by holding his back in false pain, aping the manner of a geriatric.
However, Eto'o - who is now out of contract at Stamford Bridge - has blasted Mourinho for his comments, while also insisting that he can continue playing at the highest level for the foreseeable future.
"Today, I am 33 years old - and it is not because a fool called me an old man that you must believe it," the Cameroonian told africanfootball.com.
"And you may have noticed that the old man was better than the youngsters. Some believe I am going to retire in the United States or in the Middle East, but I have regained the joy of the Champions League and I am going to carry on playing in the Champions League.
"Where? I am not going to tell you."
Eto'o is set to feature at his fourth FIFA World Cup for Cameroon next month, and the four-time African Player of the Year feels he could go on and break Lothar Matthaus' and Antonio Carbajal's record of playing at five World Cups.
"I am going to carry on playing because physically and mentally I feel great," he added.
"So I am going to go to this World Cup and to the next one when I will be 37. Some did it at 42, so I can still play at two more World Cups."
