According to a statementfrom the club, Arsenal employees who have had recent close contact with Arteta will now self isolate and that they expect this to be a significant number of people from the London Colney training centre including the full first-team squad and coaching staff, as well as a smaller number of people from our Hale End Academy which we have also temporarily closed as a precaution.

Source:https://correctkid.com/breaking-arsenal-coach-mikel-arteta-tests-positive-for-coronavirus/