The Nationals might have a problem playing in Washington:

The main reason for the uncertainty is that players, coaches and staff have to quarantine for 14 days if they are exposed to the novel coronavirus, per the city’s health protocols. D.C. is unwilling to bend that requirement for the Nationals, according to a person with direct knowledge of the situation, and the team is now wary of its ability to compete under those guidelines.

WashingtonPost.com

The are looking at their class A stadium in Fredericksburg, VA and their Florida complex as possible alternate sites.