If they did, they might not even be a playoff team.
As it is, the Packers might keep winning the NFC North year after year after year -- like they've done in 2011, 2012 and 2013 -- and yet still can't be considered a legitimate Super Bowl contender until they show they can handle the Seattle Seahawks or San Francisco 49ers.
They had their chance in one of the biggest regular-season showcases -- the 2014 opening night game against the defending Super Bowl champions -- and it was just like the 2012 game at CenturyLink Field. (Well maybe not quite like that.) And it was just like their previous four games against the 49ers since 2012.
Thursday night's 36-16 loss to the Seahawks was the worst of their six straight losses to the two teams that own the NFC West and that met in last season's NFC title game.
"You're talking about two good football teams," Packers coach Mike McCarthy said. "We've got to worry about the Green Bay Packers."
And McCarthy has plenty to worry about.
All the changes on defense that McCarthy and defensive coordinator Dom Capers made in the offseason -- including the unveiling of a 4-3 scheme they used part of the game -- still left the Packers vulnerable against the run. Marshawn Lynch rushed for 110 yards on just 20 carries, two of which were touchdowns. Multi-dimensional receiver Percy Harvin ran for 41 yards on just four carries and caught all seven passes thrown his way. The Seahawks had 400 yards total and 210 rushing until losing a yard each on three straight kneel-downs to end the game.
Julius Peppers, the Packers' high-profile free-agent signing, never put much pressure on Seahawks quarterback Russell Wilson. And when he did -- he and Clay Matthews had an apparent shared sack in the second quarter -- it was wiped out by a penalty.
"We just didn't put it together when we needed to," Matthews said. "In preseason, leading up to it, we felt real confident about this group of guys that we have, but it didn't translate over for some reason."
Defensive tackle Mike Daniels, the most outspoken about the Packers' need to improve on defense, was just as frank about his own play in the opener.
"I want to spit on the way I played," said Daniels, who had six tackles but never got near Wilson. "And I can only speak for myself. It was a pitiful performance. I know I can do way better than that."
It did not go much better on offense, and rookie center Corey Linsley was the least of their problems. Eddie Lacy ran for 6 and 15 yards on his first two carries, and then was shut down. He finished with just 34 yards on 12 attempts before leaving with a concussion in the fourth quarter. Both he and right tackle Bryan Bulaga, who re-injured the left knee that kept him out all of last season, left the game early and did not return. If Bulaga tore his ACL again, the Packers will have another major problem.
Despite completing 23 of 33 passes, Aaron Rodgers totaled only 189 yards with one touchdown and one interception on a ball that went off Jordy Nelson's hands.
Trailing by only a touchdown at halftime, the Packers' first three possessions of the second half ended with an interception, a fourth-down sack and a strip-sack for a safety.
"Fortunately, it was just one game out of 16," Matthews said. "But if we want to get to where we want to go, we're going to have to beat good teams like this. Shoot, we may even end up being back here."