Wolves manager Nuno Espirito Santo and West Ham assistant Alan Irvine have raised concerns over the length of time it takes to get Covid test results.
Both clubs said that there are currently delays in getting results because of how busy laboratories are.
And the pair both explained that their sides could set off for matches not knowing if any of their players have coronavirus.
"It's very disruptive for preparation and planning," Nuno said.
"It's tough for us, you get tested - we got tested today - and we don't know the results. We're preparing for the match on Sunday and having the stress about the final result, can you use a player, can you not?