Barcelona forward Robert Lewandowski has expressed concerns over the amount of football being played, adding that he thinks it is contributing to a decline in the quality of games.
FIFA on Thursday offered talks with global groups of football leagues and player unions to end a three-month deadlock after they threatened legal action over adding to the packed competitions calendar.
"This season is going to be more tough than before because we have more games in the Champions League ... there are the games with the club but also the national team, so we travel a lot," Lewandowski told ESPN.
"That will be a huge challenge for every club and every player, because the expectations are always very high, and you play every two days, and people expect you play every game at the highest level.
"It's almost impossible to stay on top of your game, every game, because you don't have time for resting well, you don't have time to be outside of football in your mind ... We are human, we are not machines.
"Probably in the end, the quality of the games of football will a little bit be going down because of the intensity of the games."
The Poland international added that he is not focused on Barça making new signings amid reporting that the Catalan club are interested in Dani Olmo and Nico Williams.
"Until we sign the new players I don't think about who can come to us and join us at Barcelona."
His teammate and goalkeeper Marc-André ter Stegen agreed with the 35-year-old striker, though admitted new signings would help the team.
"If there are reinforcements later, of course they'll be welcome, but for now we've already shown that we can compete with anyone," the Germany international told ESPN.
Barça play Real Madrid in a preseason friendly in New Jersey on Saturday.