Cardinals safety Rashad Johnson notes that 49ers wideout Anquan Boldin's fourth-down catch is short of the line to gain at the end of Sunday's 19-13 Cards' win.

In the locker room immediately following his team's win against the 49ers Bruce Arians, as he has done for many weeks after a win, told his veteran players they again would have Monday off.

The usual cheer that came next was cut off by cornerback Patrick Peterson.

"Defense, we will be in there by 11 (a.m.)," Peterson said to the hushed room. "We've got to fix this."

So Monday morning, defensive players who weren't already on hand arrived for the film session. They never thought twice about the request. A little extra time on what could have been an off day is worth it.

"He's our leader, you know? Has been all season," linebacker Kevin Minter said of Peterson's request.

"We all made it a point this year to do something different, to go further than this organization has been, as far as winning a Super Bowl," Minter added. "In order to do that, it's all about the little things."

There have been far too many little things wrong. That's what Peterson was making clear Sunday after the game, noting communication issues and a lack of being on the same page – not playing the way most championship defenses play.

"I have to make sure our guys are ready for this run of the season," Peterson said.

Minter noted exchange problems on calls, mixups in the secondary, players not blitzing when they were supposed to blitz. And that was just on Sunday. As he headed into Monday's meeting, he shook his head as he guessed that there would be 20 mental errors across the board.

The Cardinals only gave up 13 points, but the 49ers actually outgained the Cardinals, 368 yards to 337 yards, and while to a man players made sure to credit San Francisco quarterback Blaine Gabbert, they were not happy with the yardage total.

Safety Tyrann Mathieu was irritated the Cardinals gave up even that many points, looking at a season-long concern. Peterson's request to come in Monday to fix things? "I understand him and I feel him," Mathieu said.

"If you look at this season you'd  say, 'Oh, we've been playing some pretty good defense,' " Mathieu said. "We don't really think so. We've been capitalizing on our opportunities, catching interceptions, things like that, but the offense is playing so well it's like defensively, we relax at moments – something we wouldn't have done the previous two years.

"It's a mindset, it's an attitude, no matter what the offense is doing, there is a certain way we've been playing defense here and we have to continue that."

What motivates Mathieu is the memory of last year's late defensive slide, the one that couldn't prop up a Carson Palmer-less and then Drew Stanton-less offense as the Cardinals blew a chance at an NFC West title and were one-and-done in the playoffs.

"Thank God our offense is scoring 40 points this year but we have to get back to being that stingy defense," Mathieu said.

This is the best time to hit pause -- after a close call in San Francisco but still not a loss, as the Cardinals head into the home stretch with the No. 2 seed under their own control. A day off is nice, but there are other priorities.

"It's not much to come in here for a couple of hours," safety Tony Jefferson said. "We can go back home and rest. It's not that big of a thing. But we are still getting in extra work, quality work."

The meeting went well, coach Bruce Arians said, with the players going over play by play with the coaches' notes.

As for Peterson's locker room request right after Arians delivered his day-off speech, the coach understood.

"That's what captains do," Arians said.