The pitch clock may not be ready for prime time, but it will get a look at the highest levels of the minor leagues in the upcoming season, FOX sports reports:

Baseball owners are negotiating pace-of-game changes with the players union, but the initial adjustments will be more dramatic at the minor-league level, sources told FOX Sports.

A 20-second pitch clock will be implemented at Double-A and Triple-A, but not in the majors in 2015, sources said.

Owners could vote to approve a particular course of action at their meetings in Phoenix on Thursday, but no changes will be official until the union approves.

Other changes – including forcing managers to make replay challenge decisions more quickly – are under consideration by owners.