He said: "It's so tough. You don't just think about this season - but also next season. Let's say we win the league or cup, then go to the final of the Club World Cup; the Community Shield is three weeks after. So when do we have holidays? There are no breaks in winter, so if we are lucky we get two weeks and then we need to be back and into next season. Then the next summer it's the World Cup. There's no end to it.
"It's just game after game and I don't know how it will work out over the next couple of years. You can't just keep adding game after game and assume everything will be like it was. You have to think about the players as well. At some point you'll be too tired to play any more games. And then come injuries, definitely. We train as hard as possible and we are fit – but there has to be a limit. Maybe I'll retire at 30!"