Sheikh Muhammad Ibn Al-’Uthaymeen (rahimahullah) said, “There is no problem in playing football, given the following conditions:

1. The garment (sports gear) must cover whatever that is forbidden to be shown (i.e your aurah)


2. It should not distract from other Islamic obligations


3. It should not include cursing and bad words


4. It should not become an addiction, like playing all-day long


 
[clear]
 
As for playing it once in a while to entertain yourself, it should not be a problem. No doubt that playing football makes the body active and healthy.
 
This doesn’t mean that seekers of knowledge can play football in public spaces like at market places as this does not befit them. However, if they were to go for games (at fields or courts) of football, we don’t see any problem in it, and that does not decrease the status of a Student of Knowledge.”
 

– Etiquette of A Student of Knowledge to Himself, pg. 46, Sharh Hilyatut Tolibul ‘Ilmi by Sheikh Muhammad Ibn Al-’Uthaymeen (Silsilah Muallafaat Fadhilatis Sheikh)