The Cleveland Cavaliers announced on Monday that head coach Tyronn Lue is stepping back from coaching to focus on his health.
"After many conversations with our doctors and Koby (Altman) and much thought given to what is best for the team and my health, I need to step back from coaching for the time being and focus on trying to establish a stronger and healthier foundation from which to coach for the rest of the season.
"I have had chest pains and other troubling symptoms, compounded by a loss of sleep, throughout the year. Despite a battery of tests, there have been no conclusions as to what the exact issue is.
"While I have tried to work through it, the last thing I want is for it to affect the team. I am going to use this time to focus on a prescribed routine and medication, which has previously been difficult to start in the midst of a season. My goal is to come out of it a stronger and healthier version of myself so I can continue to lead this team to the Championship we are all working towards.
"I greatly appreciate Dan Gilbert, Koby Altman, our medical team and the organization's support throughout."
Altman said he and the team support Lue's decision.
ESPN reports that assistant head coach Larry Drew will take over.