Troxel was an assistant coach for the Phoenix Mercury back in November when he was charged with assault and disorderly conduct for allegedly attacking his fiance after a Phoenix Suns game.

Troxel severed two arteries in his arm during the incident -- in which he allegedly punched through a glass window at his home during a heated argument with his fiancee. Troxel has maintained he never laid a finger on his fiance.

In the initial police report, cops say Troxel claimed he suffered the injury as a result of an accident while putting up Christmas lights ... but while at the hospital, the fiancee told a nurse a different story.

Cops investigated and Troxel was charged with 2 misdemeanors -- but now, TMZ Sports has learned the case was officially thrown out in part because the victim refused to cooperate with prosecutors.

Troxel has issued a statement ... essentially viewing the dismissal as a victory and says he and his fiancee are together and doing just fine.

"My fiancé and I are thrilled to have this situation behind us and look forward to moving on with our lives," Troxel said.

"I cannot thank her enough for her support, love and friendship always."

"I regret getting into an argument with my fiancé the night of the incident, but I never assaulted or hurt her in any way."

Troxel's fiance Lauren Helt issued a statement saying, "I am so glad to have this nightmare behind us. It’s unfortunate that this situation was blown out of proportion. Todd has never hurt me and should never have been charged in this case. He is and has always been a loving and supportive figure in my life and I look forward to moving on with our lives together."

The Mercury publicly severed ties with Troxel after its own investigation -- but now Troxel says he's focused on getting his coaching career back on track.