"After receiving info earlier in the week 4 @ATPChallenger Quimper... rules have now changed and players who have played this week outside of EU now have to quarantine for 7 days on arrival in France.. the tournament starts in 2 days"
From our friend Yazmin.
So all those who have played Istanbul this week are no longer able to play Quimper.
Edit
In another tweet from Yazmin, she has worked out that 7 MD players will have to withdraw.