Rafael Nadal has criticized the Penn tennis ball being used at several tournaments, including this week at Indian Wells.

"With a normal ball during day and night there is differences, but with that ball is completely dramatic how the things change," he said. "During the day especially the ball is very, like you are touching a stone. There is no feeling."

The world No. 3 said the ball was resulting in a lot more errors from players. "I see a lot of player having a lot of mistakes from a lot … one meter or two meters, and that's not good for our sport," he said. "But that's what we have today. We have that ball. I think ATP and fans deserve a better ball to have a better show."

The Spaniard said he had been satisfied with previous versions of the ball, but not the most recent one. However, he does not see things changing.

"I think the players said what they have to say. Is not new. Something that happens since a while," he said. "I didn't understand very well, because the brand that is making that ball they say now is a new ball, but still bad and I don't understand why. Because if it's a new brand creating new ball, you can understand that they make not a bad ball. But the same brand five years ago had a great ball, very good ball. Is difficult to understand why today they are not able to do it."

Andy Murray said the conditions were part of the issue, but also noted a large difference in the speed at different times of the day.

“I don't know if it's only the balls,” he said. “I think it's probably a combination of a few things. You know, for me, the balls don't feel as lively … when I play at 9:30 in the morning or in the evening they don't feel as lively, but then during the day it's ridiculous how high they bounce and how quick they move through the air and jump off the court. They said they made some changes to the balls. I don't know how much of a difference they made.”