Are you talking about cup games? Or also the league? If it were the latter, there would be zero incentive to test your own players. Instead, you'd be asking them play through a potentially very damaging virus.
It makes sense, as Neal Ardley believes, that the virus got inside Notts' camp from another team (presumably Altrincham), but it's Notts who have suffered from another team's lackadaisical approach to testing (and, by extension, the government's inability to have a comprehensive, affordable testing system in place). We lost a league game we probably would have won with a full squad and then had to forfeit a cup tie we were the favourites to win.
As the cold winter months kick in, though, this will probably just become the norm rather than the exception.