They can, however, win a playoff spot by the end of the week if any of these scenarios occur:
The Packers defeat the Lions, the Vikings win at the Falcons and the Saints win or tie against the Giants.
I'll let you judge whether any of those scenarios are likely. Without mentioning any names, I'm going to say Option No. 2 represents the Packers' best opportunity. Don't forget to get familiar with ESPN.com's Playoff Machine if you haven't already.
(Hat tip to Michael Signora of NFL for these scenarios.)