Bucks fire first-year head coach Adrian Griffin after 43 games

The Milwaukee Bucks fired Adrian Griffin as head coach on Tuesday after just 43 games, despite boasting one of the league's best records midway through his first season.

The Bucks plan to quickly search for a small group of accomplished and available veteran head coaches — with Doc Rivers as a top target, sources told ESPN's Adrian Wojnarowski. The sides have not yet spoken, but the Bucks are expected to reach out soon and gauge Rivers' interest, sources said.

“This was a difficult decision to make during the season,” Bucks general manager Jon Horst said in a statement. “We are immediately working to hire our next head coach. We thank Coach Griffin for his hard work and contributions to the team.”

Veteran assistant Joe Prunty will fill in in the interim. Horst will speak at a press conference on Wednesday, ahead of the Bucks' upcoming home game against the Cleveland Cavaliers.

Milwaukee hired Griffin over the summer to replace longtime coach Mike Budenholzer, who was fired after Milwaukee was eliminated in the first round of the last playoffs. A few months after the hire, the Bucks initiated a blockbuster trade to acquire Damian Lillard – putting pressure on the franchise to win big this season.

The Bucks are 30-13 and entered games No. 2 in the Eastern Conference on Tuesday night; that's the best winning percentage for a team that fired its head coach in a season since David Blatt with the Cavaliers in 2015-16.

But despite an impressive record, the Bucks have sometimes struggled, particularly on defense. They went from fourth in defense last season to 22nd this year and just gave up 135 and 113 points in back-to-back games against the Detroit Pistons.

Griffin, 49, had spent 16 seasons as an NBA assistant, including the last five with the Toronto Raptors. This followed a nine-year playing career in the NBA.

The Associated Press contributed to this report.