Defoe was overlooked by Three Lions boss Fabio Capello when he has named his last two international squads.
But his answer has been to up his training regime and become a virtual recluse with little else on his mind other than football.
And the former West Ham star added: "In the last World Cup season I played a lot of games — and in March you do feel tired.
"That's normal, especially with the intensity of the Premier League. I think if you look after yourself, you will be OK at the end of the season."