After a brief courtship, Doc Rivers has reached an agreement in principle to become the next coach of the Milwaukee Bucks, sources told ESPN on Wednesday.

Rivers, an ESPN NBA analyst who most recently led the Philadelphia 76ers to three consecutive trips to the Eastern Conference semifinals, emerged as the top target immediately after the dismissal of Adrian Griffin. The sides negotiated deep into Tuesday night and Wednesday morning before reaching agreement on a deal, sources said.

Despite having the second-best record in the Eastern Conference, the Bucks fired Griffin only 43 games into his head-coaching career, largely because the organization came to believe it could find an upgrade who gave the team a better chance to compete for a championship, sources said.

Based on Rivers' accomplishments and availability, general manager Jon Horst planned to pursue him and persuaded him to take the job and chase his second NBA title as a coach.

The Bucks believe Rivers' history of coaching star tandems makes him uniquely suited to maximizing Giannis Antetokounmpo and Damian Lillard.

One high-level assistant coach under consideration to join Rivers in Milwaukee is Dave Joerger, sources told ESPN. Joerger, the former head coach of the Memphis Grizzlies and Sacramento Kings, spent three seasons with Rivers in Philadelphia.

Rivers has a long history in Milwaukee, where he was an All-American guard for Marquette in the early 1980s.

He has had 16 straight winning seasons since winning the NBA title with the Boston Celtics in 2008 -- a streak topped only by Gregg Popovich, Phil Jackson and Pat Riley, according to ESPN Stats & Information. His 1,097 regular-season victories is ninth in NBA history, and his 111 playoff victories is fourth all time.

Rivers does have obstacles to overcome in the postseason, including 10 Game 7 losses in his career and a run that includes five straight. He has also lost nine straight games with a chance to reach the conference finals, according to ESPN Stats & Information.

Nevertheless, Rivers gets the opportunity to tighten up the Bucks' defense and keep them in the chase for the No. 1 seed in the Eastern Conference. After he was fired by the 76ers at the end of last season, Rivers was a runner-up to Frank Vogel for the Phoenix Suns' coaching job, sources said, before accepting an analyst role on ESPN and ABC's NBA game coverage.

"We wish Doc well and we look forward to documenting the next chapter of his coaching career. We have a deep roster of supremely talented commentators who will continue to serve NBA fans with tremendous skill, passion and expertise," David Roberts, ESPN's head of event and studio production, said in a statement.

Griffin had a 30-13 (.698) record, but the Bucks had dropped from fourth in defensive efficiency last season to 22nd -- although some of that had to be attributed to the loss of All-Star guard Jrue Holiday.

Under immense expectations, Griffin was hired to replace Mike Budenholzer in June and tasked with incorporating his system into a team of star veterans. According to sources, Horst believes Griffin will develop into a good NBA head coach but had lost confidence that he could do it within the timeline of the Bucks' immediate championship window.