Kyle Shanahan explains why he remains confident in defensive coordinator Robert Saleh

The San Francisco 49ers defense gave up 521 total yards to the Green Bay Packers offense on Monday night. Quarterback Aaron Rodgers passed for 425 yards with two touchdowns. The defense allowed him to put together a 10-play, 81-yard drive in just over a minute to set up a game-winning field goal.

The 49ers defense ranks No. 25 against the pass and No. 29 in points allowed this season while only seven teams have fewer sacks than its 12. The offense has scored 27-or-more points four times this season but has won just one of those games.

While Robert Saleh's popularity among the fanbase has dropped significantly this season, head coach Kyle Shanahan offered up a vote of confidence in his defensive coordinator after Monday night's 33-30 loss.

He did so again on Wednesday afternoon.

"I have confidence in him because I've been coaching for a long time," Shanahan told reporters. "I've been around a lot of coaches, offensive coaches and defensive coaches. I have confidence in him because I should. He's very good at what he does. He's very smart, and he runs a very good system.

"Any time there's a mistake, you always look at coaches, you look at players. It's all of us. We did make too many mistakes, especially in those first 17 plays. That starts with me, it goes to Saleh, it goes to the players. We're all committed to fixing those. We have to fix those. Those do happen sometimes in games, just like it happened a lot on the other side of the ball us going against Green Bay's defense. But, it can't happen too much, and you have to clean it up.

"We had too many freebies at the beginning of the game, especially I want to say four out of those first five plays. It got a lot better after that. I think they held them to 100 yards on every single drive and six points until the two-minute drive at the end. They did respond the right way, but it was not good how we started out, and we've got to get that fixed."

Matt Barrows of The Athletic recently joined the "No Huddle Podcast" and predicted that Saleh would be back with the 49ers in 2019.

"I think that Kyle Shanahan would love to retain him," Barrows told Al Sacco. "That would be his instinct to do that because they don't want to bring in a new coordinator and have a group of young guys learn a new defense."

The 49ers defense improved toward the end of last season; something the long-time 49ers beat writer can see happening again this year.

"The question will and should arise: Why weren't they playing better at the beginning of the season?" Barrows continued. "But I think, by the end, it's a young group, they're in year two of the system, the schedule is a little bit more amenable by the end of the year. I think all those factors mean that the defense will be playing better."