Jerry Jones should just fire Jason Garrett already.

Isn’t it obvious what Jones is doing here? He has assembled Jon Gruden’s staff on Garrett’s team — Monte Kiffin as defensive coordinator, Rod Marinelli as the defensive line coach and Bill Callahan as offensive coordinator.

Yes, Callahan held that role a year ago — in name. But it was Garrett who called plays. No longer, it appears, with Jones stripping Garrett of those duties and (likely) giving them to Callahan, Gruden’s good buddy from the Oakland days and beyond.

Hey, if Tim Brown basically can suggest that Callahan threw the Super Bowl years ago to give Gruden a ring, farcical or not, we know just how close Callahan and Gruden are.

So Garrett’s not calling plays. His brother, John, the former tight ends coach in Dallas, was shipped out of town. And now it appears that Jones is trying to shove one of his former good old boys, Houston Nutt, down Garrett’s throat as the running backs coach.

Calllahan, Marinelli and Nutt — all were former head coaches. When Jones has been asked about Garrett’s game-management decisions, he has had a hard time not suggesting that he’s not fond of them in a lot of cases. And to be fair, Jones’ criticism of the erudite but also mechanical Garrett is often spot on: Too often, he overthinks and mishandles crucial game-clock situations.

But by pussyfooting around the obvious, that Jones craves having another head coach, he’s undermining Garrett badly. He’s basically hoping Garrett quits so that Jones can save a few million dollars of his salary.

It’s obvious. Painfully. And instead of just offing the guy, Jones allows him to go about his job down at the Senior Bowl with the threat looming over him that any day Jones — or Gruden — could have a change of heart and fire his head coach.

It’s weak. Maybe Jones is waiting until he knows he can get a settlement with Garrett. Maybe the owner isn’t sure Gruden wants the job. Maybe Gruden is asking too much in salary.