GREEN BAY — Mike McCarthy knew the unpleasant task ahead of him even before he boarded the Green Bay Packers' charter flight back from San Francisco late Saturday night.

"We have a long flight back, so I'm sure I'll have the offense graded before we hit the Rocky Mountains," the Packers coach said of his team's horrendous offensive performance in a 34-6 preseason loss to the 49ers at Candlestick Park, a defeat that left the Packers 0-2 in the preseason for the first time since 1993.

"We've got work to do."

The grades won't be pretty.

The first-string offense managed just 46 yards on 25 plays; starting quarterback Aaron Rodgers was sacked four times (losing 26 yards) and completed nine of 16 passes for 58 yards and a passer rating of 64.1; wide receiver Donald Driver dropped what would have been a 38-yard gain, while tight end Donald Lee dropped what would have been a 7-yard touchdown; and the offensive line shuffle didn't resolve any of the questions on the interior.

"We feel like we have an offense that will scare anybody. We have some of the best running backs and wide receivers and tight ends in the game. To put that few points on the board, that's disheartening for everyone," Driver said. "It's preseason, but you don't want to feel this way going into the regular season. We have two more games before the regular season starts (Sept. 8) on Monday Night Football against the Minnesota Vikings, and we have to show we have a good offense.

"For us to go out there on offense and really stink up the place like we did, we just didn't execute. When you don't execute, you can't make the plays. And we didn't make 'em."

After completing nine of 15 passes for 117 yards with a touchdown and an interception that wasn't his fault in the exhibition opener against Cincinnati, Rodgers admitted the offense took "a step back," and that he was primarily to blame. Not only wasn't he sharp on his throws, but he "held the ball too long" on several plays, resulting in sacks.

"There were a lot of mental mistakes on offense, every position. Myself, I made some poor decisions. When you're facing a (3-4) defense that brings multiple fronts, you have to be good with communication, and I don't think we communicated as well as we wanted to," Rodgers said. "I'm disappointed. I had a lot of family and friends (at the game) and I didn't give them a lot to cheer about."

Asked to rate Rodgers' performance, McCarthy said, "Well, the productivity wasn't there for the offense, so you can never sit and say the quarterback played well when that doesn't happen. There are some decisions I'm sure we'll look at and we'll learn from. It was not a good evening for any of our quarterbacks."

Backup Brian Brohm was 4-for-9 for 33 yards (54.5 rating) but was involved in a fumbled exchange with center Junius Coston, and third-stringer Matt Flynn was 5-for-6 for 33 yards (89.6 rating) but was blindside sacked twice, fumbling twice and losing the second.

After arriving back home around dawn Sunday morning, the players were off until today, when they'll watch the film of the game before practicing at 6:30 p.m. As ugly as it was going to be, Rodgers said he was looking forward to the screening.

"We need to be honest in our critiques of the film," Rodgers said. "I'm going to be brutally honest with myself. I know I didn't play well. We have to improve."

While their exhibition schedule of four games in 18 days might not be optimal for practicing, it will give the offense a chance at redemption in fairly short order. After practices Tuesday and Wednesday morning, they'll be right back to game action Friday night in Denver against the Broncos.

Since it's the third preseason game, the starters figure to see their most extensive playing time of the exhibition season. Rodgers said he expects the offense to play "2½ to three quarters" against the Broncos.

McCarthy was confident Saturday's poor showing would pay off in the long run.

"This is a great experience to learn from. The other team got the best of us in a number of different areas. This is an experience that I promise you our football team will learn from," McCarthy said.

"That's the good thing about playing this poorly in preseason. This is an excellent opportunity for our team to learn from this, and I'll take full advantage of this opportunity for our football team to learn from this, whether it's the quarterback, free safety, defensive linemen — throughout our football team."