That loss will stick with them forever.
That's why from coach Mike McCarthy on down, the Packers are trying to keep a lid on the hype surrounding the rematch.
"It's not as if we win this game, all is forgotten," Packers linebacker Clay Matthews said Wednesday. "I'm sure there's some extra motivation for some, but the reality is it's a very good team and it's a new season and they have the same weapons we saw last year. It should be a fun game. I know it's what the fans are looking for, and it's a good test to see where we’re at, where they're at early on."
Try as they might, they Packers can't escape references to last season's overtime playoff loss in Seattle, a game quarterback Aaron Rodgers at the time said is "going to hurt for a while."
Rodgers' tone was much different on Wednesday, when he tried to keep the hype in check.
"I think I've been a part of 30-some-odd losses as a quarterback, so every one of those sticks with you," Rodgers said. "It's frustrating when you put so much into it and you come up short. But it's a new season. When we get back here in April, you starting thinking about the 2015 team.
"I just heard we're the second-youngest team. It's a new group. There's always new players every single year. You're trying to add to the mix and hold on to the guys that you've got. We did a good job of that this year. They've got a couple new players. That's just the way the NFL goes."
Rodgers is right; the Packers have the second-youngest roster in the NFL. According to opening-day rosters, their average age was 25.23. Only the St. Louis Rams, at 24.96 were younger, according to league data released Wednesday. However, 43 of the 53 players on the roster now were with the Packers last year in some capacity (roster, practice squad or injured reserve) so there's plenty of carryover.
"It's the second game of the year," Rodgers said. "It's a long season. We're one game in. Your identity as a team is formed throughout the year. You've just got to look at it as Game 2. Every one's important, especially with a conference opponent who is a talented team. But, yeah, we've got to take care of business at home."