AP

Changes have indeed come to Valley Ranch.

Apart from the departure of defensive coordinator Rob Ryan and the change in philosophy from 3-4 to 4-3 with the arrival of Monte Kiffin, more seismic shifts are possible.

According to Chris Mortensen of ESPN, owner Jerry Jones is pushing coach Jason Garrett to relinquish play-calling duties. Per Mort, Jones also may be trying to get Garrett to fire his brother, tight ends coach John Garrett.

Mort says John Garrett is calling around the league regarding other available jobs. Which could indeed means that John Garrett fears his brother will fire him.

It also could mean that the Princeton-educated Garretts sense that Jones is trying to provoke a showdown that will result in Jason Garrett leaving as the head coach without Jones flat-out firing him. Indeed, it’s one thing for Jones to roll out of bed one morning and decide to make a coaching change. It’s quite another for Jones to want his head coach to make changes and for his coach to resist, creating an impasse that leads to only one logical conclusion.

Even if Jones is simply laying the foundation to justify a Jason-Garrett-for-Jon-Gruden swap, the issue of play-calling is legitimate. Too many times over the last two years has Garrett been unable to spin the big-picture plate of clock-management with the small-picture task of deciding what the next play will be. If, as I think I said at one point this year on Pro Football Talk on NBC Sports Network, you can’t walk and chew gum at the same time, don’t try.

So regardless of whether Jones is trying to nudge out Jason Garrett, there’s still a chance he’ll be gone sooner rather than later.