Here's some key aspects to watch for in each phase of the game from a Packers perspective...

• Offense: See how undrafted rookies perform––The first preseason game is the time when the players who are third and fourth on the depth chart will see the most action they'll receive all year long. This may be their best opportunity to impress. The Packers seem to have several talented undrafted wide receivers in Tori Gurley, Shaky Smithson, Diondre Borel and Kerry Taylor. It they are to make it beyond the first round of roster cuts, make the practice squad or even the 53-man roster, they'd be advised to take advantage of every opportunity. The same goes for the undrafted offensive linemen and running back.
• Defense: Watching the backup cornerbacks get extended playing time––Although head coach Mike McCarthy hasn't ruled any players out for tonight's game, starters Charles Woodson and Tramon Williams worked with the scout team at the team's last practice on Thursday, which gave the impression that they'll be held out of tonight's game because A) they're proven players that don't need the work and B) they'll avoid injury. Also, Sam Shields, Davon House and Brandian Ross are nursing injuries that leave their status up in the air. That leaves only three other cornerbacks, who figure to see a lot of playing time: Jarrett Bush, Pat Lee and Josh Gordy. Tonight will provide a good litmus test to see how much they've improved.
• Special teams: How the Packers will treat the kicking situation––Mason Crosby sat out most of the week with an relatively minor ankle injury, although he returned to practice on Thursday. McCarthy has said they'll play it smart with him. If Crosby does play, it will be worth watching how effective he can be on a bum ankle. It's possible they'll replace him with punter Tim Masthay, who is also the team's backup kicker, but they have to be careful not to overwork him and expose him to injury too. It's possible the Packers will go for two-point conversions instead of extra points to avoid one kicking aspect of the game. It's even possible, though perhaps not likely, they'll sign a kicker as a short-term substitute.