GREEN BAY, Wis. -- Make no mistake, the fourth-quarter magic Green Bay Packers quarterback Aaron Rodgers unleashed on the San Francisco 49ers on Monday night was nothing new. Rodgers has made a career of it.

But the San Francisco 49ers offered the opportunity by just making the simplest of communication errors. Repeatedly.

"It's simple, Day 1 football," cornerback Richard Sherman said. "Once again that's why it's frustrating because it's simple Day 1 football that we've got to figure out how to translate. … At the end of the day, if you call the perfect call and they don't run the play the way you called it, what else can you do? You call the play, a guy has man and if you don't take the man, it's going to lead to a big play. Aaron will find him if he was covered and for him to not cover him is frustrating but we've got to find a way to get that done."

The 49ers' secondary had several busts against the Packers. Mike Roemer/AP

That solution has eluded the 49ers for most of the first six weeks. Even in their better defensive performances, such as last week's loss to Arizona, the Niners busted a coverage on the first defensive snap of the game, giving up a 75-yard touchdown to Cardinals receiver Christian Kirk. Such as it was, the 49ers showed slight improvement Monday night, giving up "only" a 60-yard completion from Rodgers to Marquez Valdes-Scantling on Green Bay's first offensive snap.

The culprit, like last week, was a coverage bust that came as a result of a post-huddle miscommunication.

"On the first freakin' play, again we bust," Sherman said. "We busted simple coverages. It's a simple adjustment. You can't play like that. Later on in the game, another one, a simple play and we bust."

Those busts were the order of the day for most of the first quarter as the Packers rolled up nearly 200 yards in the opening 15 minutes. For a Niners defense that entered the game among the league's best in yards per play allowed, the big play hasn't been a consistent problem but it has come at the most inopportune of times.

Against the Packers, it was both. San Francisco allowed 10 explosive plays (runs of 10 or more yards and passes of 20 or more yards) with six Rodgers completions accounting for 225 of his 425 passing yards.

Then, almost suddenly, the Niners found a way to clamp down. Sherman said there wasn't anything special about what the 49ers did in holding the Packers to six points from the second quarter through the two-minute warning in the fourth quarter.

Aside from the lack of turnovers, it was the most consistent the Niners' defense had been against a top quarterback all year.

"We just started communicating better," free safety Adrian Colbert said. "We just started getting back into that flow of communication, just all around communication."

With the 49ers offense unable to take advantage of multiple opportunities to put the Packers away, it became evident that the onus would fall on the defense. With cornerbacks Jimmie Ward (hamstring) and K'Waun Williams (shoulder) departing because of injury, the Niners were again in flux and Rodgers took advantage.

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On Green Bay's final two drives, Rodgers heavily targeted Ward's replacement -- Greg Mabin -- and the Niners again had a costly coverage bust that turned into a 38-yard pass to wideout Davante Adams to set up the tying touchdown. Rodgers was 6-of-10 for 104 yards with a touchdown and put kicker Mason Crosby in position for the game-winning field goal.

To be sure, much of the credit for that goes to Rodgers but the Niners had him on the ropes and they know they did their part in letting this one slip away and the blame, according to the Niners falls on the players' inability to execute the defense.

"I'm not going to just hop into a defense and start calling plays," Shanahan said. "That's on Saleh and Saleh is very good at what he does. I have a ton of confidence in him, I have a ton of confidence in our scheme and they made the plays to win at the end and we didn't."

Much like the 49ers' offense is in no position to overcome turnovers, the defense can't have continued communication problems. Colbert said the focus in practice has to be on over-communicating and even taking that approach in meetings and walk-throughs.

On the surface, it seems like a simple fix and the Niners have offered glimpses of what could be if only they could consistently do what's asked of them.

"This is one of the most sound schemes in football," Sherman said. "That's why you see so many people executing it. When you don't play sound it can lead to a bust. In any scheme, if you don't play sound, it can lead to big plays. We have to find a way to just play disciplined. When we stopped them when we got three-and-outs, it wasn't anything special, it wasn't guys making stuff up, it was just guys doing their assignment. Nothing special."

Until it gets fixed, that's a description that can also apply to the 49ers defense.