Former NBL rookie of the year and NBA player Isaac Humphries will return to the Adelaide 36ers after signing a one-year contract.
Humphries played two years with the Sixers before joining United last season, where he averaged 9.6 points and 5.4 rebounds and led the NBL in blocks (1.7 per game).
But the impending arrival of 2021/22 MVP finalist Jo Lual-Acuil and NBL Next Star Ariel Hukporti's recovery from an Achilles tendon injury combined to squeeze Humphries out of Melbourne.
While playing for United, Humphries became the only openly gay player in a men's top-tier basketball league when he came out last November and received widespread support from around the world.
The 25-year-old will bolster the front-court at the Sixers, who had yet to sign an out-and-out centre for the 2023/24 campaign.
Aside from his previous stints with the Sixers and United, Humphries played college basketball for the University of Kentucky, was the 2018 NBL Rookie of the Year and managed five games for the NBA's Atlanta Hawks in the 2018/19 season.
"Super excited to get Isaac back with us and this is huge for this club," coach CJ Bruton said.
"I didn't get to work with him much during my first year as coach but his ability to impact a game from the defensive presence to his shot blocking ability to his NBA skillset, I think he is only going to grow and get stronger.
"From where he has been at, I'm excited for him and I'm excited for the club to see him back to full strength."
Import Antonius Cleveland is returning to the Sixers for a second season, while guards Mitch McCarron and Jason Cadee are among the locals on the books.