One of the Big West’s top defensive basketball teams is losing its architect.

Associate head coach John Montgomery is leaving the University of Hawaii men’s basketball team to join Chris Acker’s coaching staff at Long Beach State. Monday is Montgomery’s first day with the Beach.

Montgomery, 40, joined the Rainbow Warriors in 2015, Eran Ganot’s first season as head coach.

“I feel after nine years, it was time for a new challenge and to get closer to family,” Montgomery said. “That was the ultimate deciding factor.”

His sister, who is facing medical issues, and his parents live about an hour from the LBSU campus. His wife, Hannah, has relatives in Long Beach and San Diego.

Montgomery served as the ’Bows’ defensive coordinator. This season, the ’Bows topped the Big West in keeping opponents off the boards (31.9 rebounds per game) and were third in defensive efficiency at 105.3 (points allowed per 100 minutes).

Montgomery also worked with the post players, coordinated scouting and passing, monitored academics and admissions, and worked with the strength/conditioning staff. He was the point recruiter for guards JoVon McClanahan, Eddie Stansberry and Juan Munoz; centers Bernardo da Silva and Mor Seck, and forwards Justin McKoy, Zigmars Raimo and Casdon Jardine. He also was involved in the staff’s overall recruitment of forward Kamaka Hepa.

“We’re very appreciative of all the things he’s done for our program, and we wish him the best of luck for continued success,” Ganot said. “He comes from a great family. He has a great family.”

Montgomery will reunite with Acker, who was a UH assistant coach for two seasons through 2017. Last month, Acker, a former Chaminade University guard, signed a five-year contract as successor to Dan Monson.

“I’m definitely excited to be joining Coach Acker in his first year there and try to help him,” Montgomery said. “We’ve stayed in contact over the years since he left Hawaii and developed a strong friendship.”

But Montgomery said it was not an easy decision.

“It’s really hard to leave here,” Montgomery said. “I love Hawaii. It’ll always be my second home. I met my wife here. We have a daughter. This is a very special place. I’ll forever be indebted to Eran for the opportunity in the nine years. I’ve got nothing negative to say about Hawaii. It’s all positive. Everything has been great. The people have been great. It’s definitely going to be hard to leave.”

Montgomery’s grandfather, Jack Montgomery, was Long Beach State’s first athletic director. His father, Mike Montgomery, played at Long Beach State. Both Jack Montgomery and Mike Montgomery are members of Long Beach State’s Hall of Fame. Mike Montgomery, who coached Stanford to 12 NCAA Tournament appearances in 18 years, also was inducted into the College Basketball Hall of Fame in 2016.