(CNN)Former Major League Baseball player Jeremy Giambi has died, according to his former teams, the Oakland Athletics, Boston Red Sox and Philadelphia Phillies. Giambi was 47.
The Athletics tweeted Wednesday, "We are heartbroken to learn of the passing of a member of our Green and Gold family, Jeremy Giambi. We offer our condolences to Jeanne, Jason, and his family and friends."
The cause of death was not released.
Giambi played six seasons in the majors with four teams -- the Athletics, Phillies, Red Sox and Kansas City Royals. His final season in MLB was 2003.
The Red Sox tweeted Wednesday, "We mourn the loss of Jeremy Giambi, who spent six seasons in the major leagues, including 2003 with the Red Sox. We send our heartfelt condolences to the Giambi family."
The Phillies posted a picture of Giambi with the words, "The Phillies are saddened to hear the news about Jeremy Giambi's tragic passing. Our condolences go out to his family during this very difficult time."
Jeremy is the younger brother of Jason Giambi, who also spent his career as an MLB player.
Both Giambi brothers were featured in the Michael Lewis book "Moneyball," and later depicted in the 2011 film of the same name.