Deone Bucannon's playing time has gone up and down like a yo-yo this season.

In Sunday's 18-15 win, he was back on the field as the Cardinals used a base defense consistently against the run-heavy 49ers. The switch seemed to work, as San Francisco averaged only 3.5 yards on 31 carries despite the Cardinals defense missing run-stuffing defensive tackle Corey Peters.

"This was shutdown personnel, the first time they went to base defense this year," 49ers coach Kyle Shanahan said.

The Cardinals used Bucannon, Josh Bynes and Haason Reddick together at linebacker – the original starting trio from training camp that has rarely been on the field at the same time because of struggles. Bucannon and Bynes finished with five tackles apiece while Reddick added a pair and a tackle for loss.

Coach Steve Wilks said the switch was made to add a wrinkle against a foe the Cardinals had already played. For Bucannon, it was a reminder of old times, when he was a critical piece in the middle of the defense.

"That's what we're about – flying around, holding up in clutch situations," Bucannon said. "That's what I've been used to since I've been here. I'm glad that we're all getting a glimpse of it and getting back to what we really are."

Even though his playing time has been sporadic this season, the notoriously intense Bucannon said it has not increased his sense of urgency when on the field.

"Whether I play a lot or a little, every time I got out there I'm going to put it on the line," Bucannon said. "I can't go any harder. That's who I am."

Bucannon, who is on an expiring contract, was the subject of trade rumors earlier this month. He said he loves playing for the Cardinals and the Tuesday deadline is not on his mind.

"It's nothing I can control and nothing I'm worried about," Bucannon said. "I just know every time I'm out on the field, I'm going to put it all out there."

PETERSON ALLOWS BIG PLAY

San Francisco speedster Marquise Goodwin was held almost completely in check by cornerback Patrick Peterson, catching just one pass on four targets. The problem was that the reception, on a quick slant in the third quarter, turned into a 55-yard catch-and-run touchdown.

It was San Francisco's lone touchdown of the game. Peterson, who requested a trade earlier this week before conceding it won't happen, broke up a deep shot for Goodwin midway through the fourth quarter to keep the Cardinals' deficit at 15-10.

"He's been one of my favorite DBs in this league," Goodwin said. "I enjoyed competing against him today."

QUICK RETURN FOR BETHEA

Safety Antoine Bethea left the game late in the third quarter with a stinger. He was down on the field talking to trainers for awhile, but returned to the game quickly.

His quick return was crucial, as Bethea stopped 49ers quarterback C.J. Beathard at the 2-yard-line on a scramble on third-and-goal. The 49ers settled for a field goal, which kept the margin within two possessions, allowing the Cardinals to rally for the win.

"Four points off the board," Bethea said. "It was a big stop."