Samuel Eto'o has hit out at Jose Mourinho, telling africanfootball.com the Chelsea manager is "a fool" for questioning his age.
Mourinho suggested Eto'o may be older that he claimed in off-the-record comments broadcast by French TV station Canal Plus earlier in the season, with the striker reported to be "very annoyed" by the remarks.
The Cameroon international had memorably told Mourinho he was "a s---" during his time with Barcelona in 2005, but they later worked together at Inter Milan, winning the Treble in 2010, and the striker lavished praise on the Portuguese prior to his move from Anzhi Makhachkala to Chelsea last summer.
He ended the season as Chelsea's second top scorer with 12 goals in all competitions, trailing only Eden Hazard, but with his one-year contract nearing expiry, it appears he is certain to leave the Blues -- and he intends to prove a point by moving on to another Champions League club.
"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 said. "You may have noticed that the old man was better than the youngsters [at Chelsea].
"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. 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.
"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 [fellow Cameroon international Roger Milla], so I can still play in two more World Cups."
Eto'o, named in the 28-man preliminary Cameroon squad for the World Cup, hopes his country can make an impression this summer as they face hosts Brazil, as well as Croatia and Mexico, in Group A.
"I have never been afraid -- if you are scared, don't become a football player," he said. "But you need to have respect for your opponents.
"It will be 11 men against 11 men. It is true, Cameroon lost to Brazil in 1994, but I was part of the team which defeated Brazil at the Confederations Cup, and I scored a great goal to Dida in the 88th minute. And then we beat them again at the Olympics. It tells you that football is not an exact science.
"It is going to be difficult, for sure, but in football everything is possible. I have a lot of respect for all those great players, but I am not afraid. We will have our chances, and we need to take them.
"African nations must fight to get as far as possible and why not win the World Cup. People will say I am crazy, but if I am not crazy why would I go to Brazil? For holidays?"