MLB issued a press release detailing new rules on club house personnel and access. The most important one is this:

The overnight notice to Clubs before the arrival of Comprehensive Drug Testing personnel has been eliminated. All Clubs will be required to have a single, designated area for collections in both the home and visiting clubhouses. Collectors will be provided with permanent, official credentials and their access will be facilitated.

It's going to be tougher for people working in the clubhouse, as they'll undergo background checks and random drug tests.