McCarthy's current contract runs through the end of the 2015 season.
According to McGinn, Murphy's decision to start the contract process with McCarthy was "met by some grumbling within the team's board of directors."
One issue with giving the coach an extension stems from the uncertainty of general manager Ted Thompson's future.
As McGinn explains in depth, Thompson, 61, could choose to walk away from the organization at any time. His contract runs until after the 2016 NFL Draft -- it is unknown if Murphy has approached Thompson about a new deal.
Thompson and McCarthy represent the NFL's longest-tenured coach-general manager duo. When Thompson ultimately does decide to step away, the organization could be hamstrung in its GM search if they insist the new hire be saddled with a coach he didn't choose for the long term.
McGinn's fascinating piece dives deep into the organizational power structure unique to the Packers. The plugged-in Packers writer also suggests a few personnel men who could be Thompson's eventual replacement (John Schneider, anyone?). You can read the full breakdown, here.