Tony Clark has resigned as head of the Major League Baseball Players Association, the union announced said, as a possible salary cap fight looms during a federal investigation of its finances.

Taking more than one medication at a time is often necessary, but sometimes, medications can’t be mixed. If they are, it causes an interaction that could be serious or even deadly. Doctors say it happens more than you may think, leading to a quarter of a million hospitalizations each year in the U.S.

When baseball players agreed a decade ago to restraints on signing bonuses for draft picks, then union head Michael Weiner said matters could be revisted if the provisions didn't work to players' satisfaction.