Before the league adds teams and rearranges its divisions, it must reach a new deal with the players' union, the commissioner said.

It's been nearly three decades since Major League Baseball expanded, with the Tampa Bay Devil Rays and Arizona Diamondbacks joining the league in the 1998 season. Since then, the National Football League, National Basketball Association, and National Hockey League have each added new franchises, with the NHL leading the way by adding six teams. Many are wondering if and when MLB will add franchises to the 30 existing ones.

Commissioner Rob Manfred was asked about expansion during a Sunday Night Baseball broadcast of the Little League Classic between the Mets and Mariners. Manfred didn't give a timetable or float possible markets, instead shifting the conversation to realignment.