Boston Celtics head coach Brad Stevens is encouraged by the hard work that rookie center Robert Williams put in this past summer, according to Jay King of The Athletic.

The 6-foot-10 big man was reprimanded by Stevens after he missed a conference call and his flight back to Boston shortly after the 2018 NBA Draft. However, the former Texas A&M standout has impressed his coach with a strong work ethic, a desire to get better, and an ability to pick up on things quickly.

The Celtics have tasked their G-League associate head coach Alex Barlow to become a mentor or life coach to their talented big man. Barlow, who is only 26 years old and played for Stevens at Butler University, will be responsible for helping Williams acclimate himself to the NBA.

There is a strong possibility that Williams might start the upcoming season with the Celtics' G-League affiliate, the Maine Red Claws. He was diagnosed with a vascular disease in both legs this summer that might require surgery in the future if it becomes degenerative.

Williams was considered by some analysts to have the talent of a lottery pick but was drafted by the Celtics with the 27th overall pick because of his work ethic and, possibly, a few potential medical red flags. He averaged 10.4 points and 9.2 rebounds per game during his sophomore season for the Aggies before opting to enter the draft.