Former New York Knicks player Anthony Mason is reportedly improving after having a heart attack on Wednesday. 

News reports the evening of the attack indicated that Mason was "fighting for his life" and needed a heart transplant. On Thursday, he showed signs of improvement. 

"Right now, it's day to day, but that's an improvement from moment to moment," Mason's former agent, Don Cronson told the New York Times, after allegedly receiving updates from Mason's family. 

The New York Post reported that the 48-year-old has suffered heart problems over the past year, and has congestive heart failure. He has undergone several surgeries, and was already at the hospital when the heart attack occurred. 

The Knicks, its executives, and former players tweeted support for Mason as he recovers from the medical emergency. 

"Our thoughts and prayers are with Anthony Mason and his family. #Knicks," the organisation's official twitter account posted. 

"Praying for my former teammate Anthony Mason!!!" former Knicks star John Starks wrote. 

Knicks General Manager Allan Houston, NFL great Boomer Esiason, and many others also shared messages of prayer and encouragement for Mason and his family. Mason's eldest son expressed thanks for the outpouring of support. 

"My Family would like to thank everyone for their Prayers and Support for our Father#PrayForBigMase," he wrote. 

Mason played five seasons with the Knicks, and was the NBA's Sixth Man of the Year in 1995. He retired from the Milwaukee Bucks in 2003.