Godolphin are in "no rush" to appoint a new trainer at Moulton Paddocks in Newmarket after Mahmood Al Zarooni was banned for eight years.
Al Zarooni lost his licence last Thursday after admitting to administering anabolic steroids to 15 horses in his care.
The British Horseracing Authority said last week Godolphin have around 10 days to find a replacement for Al Zarooni if Moulton Paddocks is to remain active as a licensed training stable this season.
But Godolphin racing manager Simon Crisford said the most pressing issue is to ensure the yard is "clean of drugs".
He told the Telegraph: "Sheikh Mohammed has ordered a lockdown at Moulton Paddocks and it doesn't matter if those horses don't race again this season.
"His priority is to see that it is clean of drugs. The testing will take place this week.
"There is no rush to appoint anybody to train there at present.
"As far as we could see, the yard became inoperative when Mahmood Al Zarooni was banned and his licence was cancelled.
"What Sheikh Mohammed has stressed to me is the need to clean up this mess as quickly as possible."