New Bulls coach Billy Donovan has started the staff shakeup

Further evidence that these are not your big brother’s Bulls was -offered up Monday.

Coach Billy Donovan began the overhaul of the team’s coaching staff by letting go of four assistants — Roy Rogers, Nate Loenser, Karen Stack Umlauf and Dean Cooper.

The organization made it official in the afternoon with a statement.

Those moves open the door for Chicago-born Hall of Famer Maurice Cheeks — a longtime Donovan assistant — to return home and join the staff.

Bulls COO Michael Reinsdorf values getting this reboot of the front office as right as he can, so money isn’t an issue.

Loenser is a great example of that attitude.

His contract was up months ago, but executive vice president of basketball operations Arturas Karnisovas was still evaluating former coach Jim Boylen and the rest of his staff, so he allowed Boylen to have some say in Loenser being re-upped.

But Boylen eventually was fired, Donovan was brought in and Loenser’s office became a temporary storage room Monday morning.

A source confirmed that Stack Umlauf was demoted from her -position months ago under Boylen, but that move was never made official.

Karnisovas and Donovan had been vague about the coaching staff when queried about it last month.

“Obviously, there are staff members there that are still with the Bulls,’’ Donovan said. “I also think the other piece of it, too, with our staff is how we build out the best staff that I can work with and that can work with me, work with Arturas.

‘‘So that’s something we’re certainly going to look at from top to bottom, not only maybe around the league but certainly the coaches that are in Chicago right now.

“I look forward to talking with those guys and having some conversations. [Karnisovas] will be part of that. We’ll work together on that.

‘‘The biggest focus for us right now is how we put together the best group that we can to help the players.’’

That mission obviously is underway.

“I appreciate the time that I was able to spend with Dean, Nate, Roy and Karen,’’ Donovan said in a statement.

“I really want to thank all of them for their service and commitment to the Chicago Bulls. This is the tough side to our business, and I wish all of them the best moving forward.’’