MLB designates Atlantic League as its 1st 'partner league' Last updated : Sep 25, 2020 20:09 SportzPower Team Sep 24, 2020 17:09 Read more about MLB designates Atlantic League as its 1st 'partner league'Log in to post comments NEW YORK: Major League Baseball (MLB) announced Wednesday that it has named the Atlantic League of Professional Baseball (ALPB) its first “Partner League”.