Can you imagine that? The future Hall of Famer carrying a clipboard for a guy who has never started an NFL game?
Of course, anyone with any sense knows that situation would never work.
First of all, the Packers aren't likely to pay $10 million for a backup QB. Even more of a problem, however, would be the pressure it would place on Rodgers' shoulders. With every interception... heck, with every overthrow or one-hopper he delivers, the chants for Favre would grow. With every loss, the second-guessing by the media would increase.
Regardless, though, of whether Favre ends up on the Packers roster or the roster of another team, as long as he is in an NFL uniform he's going to make life tough on Rodgers. If Favre does eventually land with another team in a starting role, there will be constant comparisons between the two. So unless Rogers clearly outplays Favre, there will be a significant faction among Packers fans that will resent the team's decision to not welcome back a guy who has been the face of the franchise for more than a decade-and-a-half. And much of that resentment may be directed at Rodgers.
However Favre returns, assuming he does, it seems like a no-win situation for Rogers to me. He either loses his starting job or constantly battles the ghost of a legend. Anything short of looking like a legend-in-the-making himself would make it very tough to escape Favre's shadow.

