"It is with profound sorrow that we announce the passing of Marvin Miller," said current MLBPA chief Michael Weiner in a statement on Tuesday.

Miller had been diagnosed with liver cancer in August.

"All players past, present and future owe a debt of gratitude to Marvin, and his influence transcends baseball.

"Marvin, without question, is largely responsible for ushering in the modern era of sports, which has resulted in tremendous benefits to players, owners and fans of all sports."

Miller helped major league players form a union in the late 1960s and served as the union head until 1982.