Liverpool striker Fernando Torres fears playing in the Barclays Premier League could damage his health for life.
The 26-year-old, in his third season at Anfield following a move from Atletico Madrid, is currently sidelined with a knee surgery and battling to be fit to represent Spain at the World Cup.
"The Premier League is such a tough competition and I have always admired this championship and the players who are here," he is quoted as saying in the News Of The World.
"This is my third season and I'm still amazed to see (Steven) Gerrard, (Wayne) Rooney and (Frank) Lampard, players who have been here a long time, still playing at such a high level and with such impressive rhythm because the English league really wears down a player.
"I just can't imagine what state I'll be in within five or six years if I continue to play here - it could easily give me problems when I stop playing. The physical level is superior to all other countries."