Mourinho, who repeatedly criticised his strikers for failing to find the net during the season, was caught on camera earlier this year suggesting Eto’o was older than his official age.
Eto’o attempted to brush off the incident by pretending to be an old man as he celebrated his next goal for Chelsea, but the 33-year-old has vowed to prove the Portuguese coach wrong.
“Today, I am 33 years old. And it is not because a fool called me an old man that you must believe it,” Eto’o 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.
“But I am going to carry on playing because physically and mentally I feel great.
“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 in two more World Cups.”