Mavericks Fire GM Nico Harrison 9 Months After Luka Doncic Trade

9:30 AM PT -- Nico Harrison is officially gone -- the Mavs announced Michael Finley and Matt Riccardi will serve as co-interim general managers moving forward.

Mavs governor Patrick Dumont released a statement on the matter ... saying, "This decision reflects our continued commitment to building a championship-caliber organization, one that delivers for our players, our partners, and most importantly, our fans."

Nico Harrison's minutes are numbered in Dallas -- the Mavericks are expected to part ways with the general manager who shipped franchise player Luka Doncic to Los Angeles earlier this year on Tuesday.

The report came from Shams Charania just minutes ago ... who stated the team intends to cut the ties with the former Nike exec at 8 AM PST.

The Mavs are 3-8 so far this season ... but the move was pretty much expected way back in February, when Harrison -- who became the GM in 2021 -- made the head-scratching decision to trade the Slovenian superstar for Anthony Davis.

The backlash over the transaction never settled ... and even Monday night, "Fire Nico" chants rang out as the Mavs fell to the Milwaukee Bucks at home.

The future could be bright in the Lone Star State -- 2025 No. 1 overall pick Cooper Flagg had his best outing of his rookie season with 26 points in the loss ... which could be a confidence boost after a slow start out of the gates.

The roster has some talent -- AD, Kyrie Irving and PJ Washington are the top players ... but with no Luka, folks have been pretty disconnected.