I wonder if it would be easy for the players to play football with masks.
No. it will be difficult for their breathing to play football it really needs a quick breath if wearing a mask it will be hampered and it could be that they are exhausted because of breathing and I think the competition using a mask will be a lot of protest from the parties.
It would be very hard to breath with them and it might have negative impact to their performance due to the limited air that will be flown to their lungs. It is a good solution for protection to those who are sitting on the bench though.
This is still a polemic and I don't think this will happen except on the bench that you say is true, I think the higher-ups are still discussing this when football will start again.