As he got older, Jayson’s father acted as his trainer and coach to help him achieve his dream of playing basketball professionally. The Celtics star has said that neither his mother nor his father “took it easy” and “were extremely tough” on him, especially his dad. Speaking to Graham Bensinger in October 2022, Jayson got candid about how his father’s coaching “put a strain” on their relationship.

“I feel like I missed out on a father-son relationship,” he said. “Me and my dad only ever went to games or practice and to get haircuts. We didn’t go to amusement parks. We didn’t go to picnics, or fishing, or really have father-son talks because it was just all basketball.”

Jayson said that his father would often swear at him and embarrass him in front of his teammates, including throwing the ball at him. He explained, “In his eyes, he wanted me to be the toughest. He wanted me to be the best.”

“And that was his way … like if he made me upset, I would play better and in a sense, I did,” he continued. “I would get so upset. I would get so angry that I would play better.”

Despite the difficult relationship he had with Justin growing up, Jayson cites the tough love he received from him as the reason for his success today. He explained, “He was so tough on me, which I appreciate, because I wouldn’t be here if he wasn’t.”

In the years since, Jayson has grown very close with his dad, and the father-son duo have mended their relationship.