"Earlier today, I learned that four very small tumors have been found on my brain, following an MRI on Friday at a West Palm Beach facility," Carter, 57, said in a statement. "I am scheduled to be examined further Thursday at Duke Medical Center, and we will learn more at that time about my diagnosis."
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Carter, nicknamed Kid, was one of the key components for the Mets' 1986 championship team. An 11-time All-Star, he started his 19-year career in Montreal; the Expos traded him to the Mets in 1984. He spent five years in New York and was inducted into the Hall of Fame in 2003.
During the '86 season, Carter batted .255 with 24 home runs and 105 RBIs. He finished his career with 324 home runs and was twice named the MVP of the All-Star Game.
Former teammate Dwight Gooden checked in Saturday on his verified Twitter account, saying, "Being that it is the 25th anniversary of the 86 Mets . . . I'm sure my man Gary Carter will pull through just as we did as a team in 86. You're in my thoughts and prayers . . . Doc."
Mookie Wilson, now the Mets' first-base coach, issued a statement through team spokesman Jay Horwitz. "I really just found out about this today," Wilson said. "Rose [Wilson's wife] and myself send our thoughts and prayers to Gary, Sandy and the rest of the Carter family."
Ex-teammate Keith Hernandez said in a statement: "I'm shocked at the news. It gives us all a sense of our mortality. Gary was a great teammate and naturally my prayers are with him and his family."
Carter was a two-time Manager of the Year in the Mets' farm system. In 2005, he won the award with the Gulf Coast League team. A year later, he earned the same honor after leading Class A St. Lucie to the Florida State League title.
"On behalf of the Mets organization, our thoughts and prayers are with Gary, Sandy [Carter's wife] and the entire Carter family," Mets chief operating officer Jeff Wilpon said yesterday in a statement.
Carter also played for the Giants and Dodgers before returning to Montreal in 1992 for his final season.