The Chicago Cubs and White Sox are among several teams across Major League Baseball yet to be approved for 100% capacity, and both clubs are not happy about it, according to sources.

There's growing frustration among the Cubs and White Sox, even with the state of Illinois having approved a move to its final phase of reopening on June 11. That would allow businesses to operate at full capacity, but the city of Chicago has to sign off before the Cubs and White Sox can welcome full crowds back.

"Currently, Chicago is in the Bridge Phase of its reopening plan, and seated spectator events remain at 60% capacity," the mayor's office said in a statement.

"Capacity limits will lift once Chicago enters Phase 5. The COVID data has been very promising of late, and we continue to watch it closely as we consider next steps."