James Duncan has been axed as Brisbane coach, with management losing faith after the NBL club's 3-6 season start.
The recruitment of Boomers star Aron Baynes and NBA veteran Tyler Johnson came with championship aspirations in Duncan's second season at the helm.
But, after a 10-18 record last season and two of their three victories this year coming against the last-placed Illawarra, club bosses have lost patience.
Two-time NBL champion and Bullets head of basketball Sam Mackinnon will lead the Bullets as interim head coach.
Bullets CEO Peter McLennan travelled to the United States to meet with ownership that includes former NBA guard Kevin Martin, Milwaukee Bucks guard Khris Middleton and Toronto Raptors forward Thaddeus Young.
The NBL have maintained a 25 per cent share in the club that has failed to genuinely contend for a title since rebirthing in 2016 after an eight-year absence.
"JD is a high character individual, and just an all-round great guy which makes this all the more difficult, we felt the time was now to pivot and take a change of direction," McLennan said.
"We will work at pace and diligently consider our next steps for the organisation.
"The club would like to sincerely thank JD for his hard work and commitment over the past year and a half and wish him all the very best in his future endeavours."
Sports agent and executive Jason Levien, and the co-owner of English Championship soccer team Swansea City Jake Silverstein also have a stake in the the club.