With proper care and discipline there is no reason he cannot have a long productive career. Ron Santo who played for the Cubs in the ‘70s comes to mind.
Jay Leeuwenburg had a successful NFL career while dealing with Type I diabetes.
Hall of Fame pitcher Catfish Hunter was an insulin dependent diabetic. He worked hard to increase awareness about the disease when many still thought it was a death sentence.
One of my buddies on my HS football team was a diabetic. Didn’t slow him down at all and he was one of our best safeties, he would just have to hook himself up to his pump during halftime. He went on to play in college in fact.