The Milwaukee Bucks have fired head coach Adrian Griffin.

The Bucks announced the decision Tuesday afternoon alongside a statement from general manager Jon Horst, confirming earlier reports.

“This was a difficult decision to make during the season,” Horst said via the statement. “We are working immediately toward hiring our next head coach. We thank Coach Griffin for his hard work and contributions to the team.”

The reason for Griffin's dismissal wasn't immediately clear. Assistant Joe Prunty will take over as the interim coach. Horst will take questions from media on Wednesday.

Doc Rivers reportedly negotiating for job

ESPN's Adrian Wojnarowski and The Athletic's Shams Charania reported Tuesday that veteran NBA coach Doc Rivers is a top candidate for the job and was already negotiating with the Bucks. Per Charania, Rivers started working as an informal consultant to Griffin in recent weeks at the Bucks' request.

Golden State Warriors assistant Kenny Atkinson is also being considered for the position if negotiations with Rivers don't lead to a deal, per Charania.

Griffin's dismissal arrives 43 games into his tenure as head coach. The Bucks hired Griffin in the offseason to replace Mike Budenholzer, who was fired after the Bucks lost to the Miami Heat in the first round of the playoffs as the No. 1 seed in the East.

The job was the first for Griffin as an NBA head coach. He previously spent 15 seasons as an assistant with the Bucks, Chicago Bulls, Orlando Magic, Oklahoma City Thunder and, most recently, the Toronto Raptors. He played nine seasons in the NBA from 1999-2008.

Bucks are 2nd in the East, lag defensively

Griffin took over a revamped roster featuring newly acquired seven-time All-Star guard Damian Lillard alongside two-time MVP Giannis Antetokounmpo. The Bucks parted with All-Star and five-time NBA All-Defensive Team guard Jrue Holiday as part of the Lillard deal.

The Bucks are off to a 30-13 start, good for second place in the East, 3.5 games behind the Boston Celtics. Their defense has lagged compared to seasons past. They ranked 22nd in the league in defensive efficiency at the time of Griffin's dismissal. Expectations in Milwaukee are for the Bucks to compete for an NBA championship.

Prunty has 24 years of experience as an assistant coach and has worked as the interim coach for the Bucks before. He was an assistant on Jason Kidd's staff and took over the Milwaukee bench for the last 37 games of the 2017-18 season after the Bucks fired Kidd midseason. Prunty rejoined the Bucks from the Atlanta Hawks this season as an assistant on Griffin's staff.

Quick return to bench for Rivers?

Rivers has 24 seasons of NBA head coaching experience and led the Boston Celtics during their 2007-08 championship season. He most recently coached the Philadelphia 76ers for three seasons.

The 76ers fired Rivers in the offseason after repeated disappointing postseason results that saw them fail to advance past the second round of the playoffs during his tenure despite featuring six-time All-Star and reigning MVP Joel Embiid on the roster.

This season is the first since 1998-99 that Rivers hasn't been on an NBA sideline. He's worked as an analyst this season on ESPN's top broadcast team alongside Mike Breen and Doris Burke.