Celtics Coach Udoka Blindsided Nia Long, Let Her Move Fam to Boston 2 Weeks Ago

Nia Long says she's gonna need all the support she can get after getting blindsided by her fiance, Celtics Coach Ime Udoka ... who we've learned kept her in the dark about his affair, even though the team busted him months ago.

Sources connected to the team and the couple tell TMZ ... Nia had moved to Boston with Kez, her 10-year-old son with Ime, just 2 weeks ago, and the couple was house hunting.

The sad twist for Nia is that when she moved, Ime was already fully aware his affair with a married front office staffer was about to blow up. We're told Ime knew way back in July the team was aware of the affair, and was launching an investigation.

Meanwhile, we're told Nia only found out about it in the last few days ... and only because Ime knew it was about to go public.

Nia tells TMZ, through her rep Shannon Barr ... "The outpouring of love and support from family, friends and the community during this difficult time means so much to me. I ask that my privacy be respected as I process the recent events. Above all, I am a mother and will continue to focus on my children."

The social media backlash against Ime, and support for Nia, was swift as soon as the Celtics announced on Wednesday they'd be punishing him.

On Thursday night, the Celtics officially suspended him for the entire upcoming 2022-23 season.