Why can't Neymar play against Cristiano Ronaldo on Friday? Explaining Saudi Pro League rule keeping Al Hilal star out of Al Nassr game

Ronaldo and Neymar are two of the most famous footballers in the world, so it would be a huge match if they played against each other.

However, Neymar will not be able to play against Ronaldo on Friday because of a rule in the Saudi Pro League.

According to the rule, teams can only register eight foreign players in their squad. Al Hilal, Neymar's team, already has eight foreign players registered, so they cannot add Neymar to the squad.

Ronaldo made his debut for Al Nassr in a friendly match against Lionel Messi's Paris Saint-Germain on Thursday.

He scored a goal in the match, but Al Nassr lost 5-4.

Ronaldo is expected to make his competitive debut for Al Nassr on Friday against Ettifaq.

It is unclear if Neymar will be able to play against Ronaldo in the future.

The Saudi Pro League season runs from August to May, so there is a chance that Neymar could join Al Hilal in the summer and play against Ronaldo next season.