Former Boston Red Sox pitcher Tim Wakefield, whose unpredictable knuckleball flummoxed opponents during a career in which he won two World Series championships, died on Sunday after a battle with brain cancer. He was 57.

The rubber-armed Wakefield, who played 17 seasons for Boston after two years with the Pittsburgh Pirates, is third on the Red Sox list for career wins (186), six short of the team record held by Cy Young and Roger Clemens.

Also known for his charitable work, Wakefield was given MLB's Roberto Clemente Award in 2010, presented to the player who best reflects the spirit of giving back to the community, for his work with charities assisting needy children.

"Tim's kindness and indomitable spirit were as legendary as his knuckleball," said Red Sox Principal Owner John Henry.

"He not only captivated us on the field but was the rare athlete whose legacy extended beyond the record books to the countless lives he touched with his warmth and genuine spirit."

(Reporting by Frank Pingue in Toronto; Editing by Christian Radnedge)