Richard Sherman’s teammates on the San Francisco 49ers defense haven’t experienced much success. They haven’t experienced much of anything really.

Sherman is 31 years old and a Super Bowl champion. Only two other members of the 49ers regular starting defense are older than 26. Jimmie Ward is 28 and Jaquiski Tartt is 27. Nobody else on the 49ers defense can match Sherman’s NFL resume. Not even close.

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For the past few weeks the 49ers have heard a lot of praise, which hasn’t happened much since the Jim Harbaugh era ended. They’re 8-0 after Thursday night’s 28-25 win against the Arizona Cardinals that was a lot closer than anticipated. Instead of celebrating another victory, Sherman was critical of himself and his teammates following a win.

“You’re thankful for the offense,” Sherman said. “We let us down, myself included.”

Part of his message had to be the mental side of the game, prodding his teammates to remain sharp while being praised as one of the best teams in the NFL. But Sherman was happy to point out the miscues.

Richard Sherman: Win was ‘humbling’

When Sherman, who has played very well this season, speaks it should carry a little extra weight. He was part of a mini-dynasty with the Seattle Seahawks. He knows what it takes to win and keep winning.

And what he saw on Thursday night, with Cardinals running back Kenyan Drake rushing for 110 yards just three days after being acquired in a trade and quarterback Kyler Murray hitting a few big plays, wasn’t good enough.

“It’s humbling, it’s humbling for the defense,” Sherman said. “We need to be humbled. It was a humbling game. You need to be humbled on all levels. I think there was accountability on all levels. We’ll watch the tape and we’ll watch it critically. Everybody will watch it and judge themselves critically. That’s not championship football.”

Note that Sherman was adamant about the defense needing to be humbled. In the four games after San Francisco’s bye week, the 49ers gave up 23 total points and 180.3 yards per game. Everyone around the NFL has taken notice of their great start. Then they gave up a season-high in points and yards on Thursday night against a team with a rookie quarterback and head coach.

Late in the game, with the 49ers trying to close out a win, rookie receiver Andy Isabella scored an 88-yard touchdown to get the Cardinals back in the game. The 49ers were good enough to still hold onto the win, but the NFC’s projected playoff field looks very tough and they probably can’t get away with that type of performance against Aaron Rodgers, Drew Brees or Russell Wilson.

49ers cornerback Richard Sherman of the San Francisco 49ers breaks up a pass on Thursday night. (Getty Images) More

Sherman outlines the issues

Playing a road game on a Thursday night, against a tricky offense, isn’t easy. And if you take away the 88-yard touchdown, the 49ers’ performance looks a lot better.

Sherman will use the breakdowns as motivation. Sherman said Arizona didn’t do anything unexpected.

“Nothing, nothing. They didn’t do anything that was really difficult,” Sherman said. “The quarterback ran from time to time. We missed plays. We missed tackles. We blew assignments. It’s mistakes you can’t make.

“That’s not winning football. Thank goodness our offense played great.”

Sherman talked about blown assignments, players being in the wrong spot and missed tackles. He bemoaned fundamental mistakes. He took responsibility for his own play too, saying he took a bad angle and missed a tackle on Isabella’s long touchdown.

The 49ers will be fine. They have a lot of talent and haven’t had many letdowns this season. And they can fix whatever happened following a win, which always helps. Imagine how upset Sherman would have been had the 49ers lost.

“It’s not about the results. It’s never about the results,” Sherman said. “It’s about the process. It’s about doing things right.

“This is the epitome of ‘a lot to work on.’”

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Frank Schwab is a writer for Yahoo Sports. Have a tip? Email him at shutdown.corner@yahoo.com or follow him on Twitter! Follow @YahooSchwab

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