One of the strongest unions in the U.S. over the past 50 years, in any industry, is now facing one of its toughest battles in its history. And instead of that battle happening against management, it’s occurring from within.

The MLB Players Association, for the past week, has been enveloped in an accelerating leadership struggle in which a group of players are pushing to oust deputy director Bruce Meyer (above, left) and replace him with Harry Marino, a former MLBPA lawyer who was instrumental in the recent unionization of minor league players. Over the weekend, that battle went public with Marino, union executive director Tony Clark (above, right), and the MLBPA’s executive subcommittee each issuing public statements seeking to advance their cause.

“Player representatives have made clear their desire to hire a different lead negotiator and pursue a different vision for collective bargaining, as well as to obtain an independent, third-party audit of the union’s financial activity,” Marino said. “The events of the past week have been messy. But the MLBPA, like all unions, is a democracy. And democracies are messy.”