Spain goalkeepers David De Gea and Pepe Reina and Germany's Marc-Andre ter Stegen were critical of the ball that will be used at the World Cup after playing with it in a friendly on Friday night.
The Adidas Telstar 18 was used in the 1-1 friendly draw in Dusseldorf, but the goalkeepers said the ball was hard to judge from distance.
"I bet you as much as you like that we'll see at least 35 goals from long range [in Russia], because it's impossible to work out," Reina said, according to AS. "And it's covered in a plastic film that makes it difficult to hold on to. Goalkeepers are going to have a lot of problems with this ball."
De Gea agreed, calling the ball "really strange" adding: "It could have been made a lot better."
Reina and Ter Stegen both said FIFA should look to swap out the ball before the World Cup begins in June, though the German keeper accepted that it was unlikely anything would be done.
"The ball could be better; it moves a lot," Ter Stegen said. "But I think we're just going to have to get used to working with it, and try to get to grips with it as quickly as possible before the World Cup starts. We've got no other option."