Former 13-year NBA veteran forward Anthony Mason is "literally fighting for his life" due to a serious heart ailment, a source close to Mason confirmed to

Mason suffered a heart attack several days ago and has since had multiple surgeries at a New York hospital, the source said. "We're just hoping for the best at this point," the source added.

The New York Knicks, one of the six teams Mason played for, tweeted out a message of support for the 48-year-old on Wednesday evening.