Major League Baseball is now requiring teams to "muddy" baseballs before games using the exact same technique, according to a memo sent to all 30 clubs.

Muddying is the process of removing gloss from new baseballs to give pitchers a better grip. It's been used for decades and is even more important now considering the league's crackdown on the use of foreign substances over the past 12 months.

In past years, muddying involved clubhouse attendants preparing baseballs by rubbing Delaware River mud -- which comes in a can -- days before each game.

They'll now be required to continue to muddy balls on game day only and all with the same technique.