Carlos Alcaraz offered a blunt assessment of the tennis calendar in September, saying it will "kill us in some way".
Alcaraz and five other top players featured in the Six Kings Slam exhibition in Saudi Arabia last week. And the Spaniard is one of several to speak out about what they feel is a packed calendar affecting their physical and mental health.
However, others have said players do not help themselves by taking part in exhibitions. Three-time Grand Slam champion Andy Murray said some players can be "a little bit hypocritical" when it comes to discussing the schedule.