He said: " I believe that I can play beyond the age of 40. I think sports science, as well as the way I have always looked after myself, gives me the chance to do that.
"I honestly believe that in future you will see generations of players carrying on at the top level beyond the age of 40 because sports science, sports medicine, will give them that opportunity.
"All I know is that whatever plans I may have I do not want to retire yet
"I want to go on playing for as long as possible and I think that can still be for several years yet."