By Mike Morgan

Since Doc Rivers was hired as the Sixers’ coach, they hired a new boss for him (Daryl Morey), and also traded away a massive contract and poor fit in Al Horford.

The NBA enters the 2020-21 season with nine new coaches, which is a lot but not a record. Nor is it new for roster changes to occur after the coach is hired — rare is it for a team to remain entirely intact from one season to the next, especially when things were shaky enough for the coach to be shown the door.

The truncated offseason, with trades, the draft, and free agency dropping in the same week, six playoff teams needing to hire a coach, and the ongoing era of player empowerment has changed the complexion of the job for most (but not all) of the league’s new coaches from the day they were hired. At least a little.

Rivers was hired on Oct. 3

“We’ll work together — that’s one of the things that was so exciting about this job, to have that opportunity with Elton.”

The Sixers hired Morey on Nov. 2 as their president of basketball operations, placing him above Elton Brand in team hierarchy and infusing at the top of the organization an analytics-crazed, huge-trade machine in Morey.

Rivers was not hired by his boss.

In the near term, though, Rivers’ primary task was to see if he could find a way for Joel Embiid and Ben Simmons to click together on the court, to figure out how to get the most out of the Sixers’ super tall, talented roster, and determine where Al Horford fits.

Morey dealt Horford to Oklahoma City and brought in Danny Green, who’s been streaky the last few seasons but gives them much-needed shooting. And you can’t discount Morey trading Simmons, even if he says now he won’t, which would obviously be a historic shakeup.

“They’ve won 65 percent of the games they’ve played, right, so it clearly works when they play together,” Rivers said, of Embiid and Simmons. We’ll see.