Massachusetts Gov. Charlie Baker says the state's five professional sports teams -- the Boston Red Sox, Boston Celtics, Boston Bruins, New England Patriots and New England Revolution -- can resume practicing at their respective facilities on June 6.

But Baker made clear the reopening of those facilities must be done in accordance with the health and safety rules that each of the leagues is developing.

The Celtics announced they will begin voluntary individual workouts at their facility on Monday. Workouts will be conducted in accordance with city, state, CDC and NBA requirements, with only four players allowed to work out at a time.

NFL commissioner Roger Goodell said Thursday, after an owners conference call, that the virtual offseason is being extended for two more weeks. In a memo sent to the 32 teams and obtained by The Associated Press, he outlined the next phase of reopening of club facilities, which can begin Monday.

NBA teams have allowed players back at their training facilities for voluntary sessions since May 8, with more than half of the league's franchises having already taken advantage of that opportunity.

The NHL, which is ironing out details to resume its season by jumping straight to a 24-team playoff format, released a memo this week saying it is targeting early next month as the start date for Phase 2 of its return-to-play protocol. It includes the opening of practice rinks and allowing small, voluntary group workouts on and off the ice.