The call comes after Roger Federer and Rafael Nadal – ranked one and two in the world – were forced to pull out of the ATP’s Hamburg Masters this week after being worn out after a gruelling five-set final in the Rome Masters last weekend.

Said Horst Klosterkemper, managing director for Europe at the ATP: “We have to come up with a concept of a calendar and a new structure.

“No-one is happy with this situation, not the sponsors, the television channels nor the spectators.”