If there is no lockdown among the general public I don't see how cancelling a few games reduces their chances of catching it at all. Their partners, children, friends, family etc will all still be exposing themselves to it among the public, work, school etc. Being outside on the training pitch is probably one of the least risky places the players will be.
Letting fixtures pile up so they later play an obscene number of games in a few days seems more likely to cause problems then fielding a mix of first team and youth team players for a few games.