By JOSH DUBOW AP Pro Football Writer

SANTA CLARA, Calif. (AP) — Any encouragement the San Francisco 49ers might have gained from last week’s win at Chicago was wiped out in a hurry against a short-handed Arizona team missing most of its top playmakers.

Now, after the 31-17 defeat to the Kyler Murray-less Cardinals on Sunday left the Niners winless in four home games, a season that began with high expectations is spiraling out of control.

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“It’s pretty embarrassing,” linebacker Fred Warner said. “It’s unacceptable for sure. This is one of those that you have to move past quick, because it was embarrassing just defensively what we put on tape. It’s something you want to get that taste out of your mouth and get right back to work.

The 49ers (3-5) made plenty of errors on Sunday that proved to be far too much to overcome, even against a team missing Murray and receivers DeAndre Hopkins and A.J. Green.

The Niners lost a pair of fumbles after big gains in the first half, were repeatedly gashed on defense and fell into a big hole they couldn’t get out of as they lost for the fifth time in six games to fall 4 1/2 games behind the Cardinals in the NFC West.

“It’s tough when you turn the ball over twice early on when you’re moving the ball after explosive plays,” tight end George Kittle said. “That kind of just kills the team and doesn’t help our defense out at all. We started with a couple of three-and-outs. That’s tough for (the defense). It’s a lot of ball early. As an offense, we have to execute better. We have to take care of the football.”

Kittle, in his first game back from a calf injury, lost a fumble on the second drive of the game. Brandon Aiyuk lost another two drives later and the Niners fell behind 17-0 in the second quarter.

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Kittle caught a TD pass from Garoppolo late in the first half to give San Francisco some life, but that was quickly extinguished when James Conner caught a short pass in space from Colt McCoy and raced 45 yards for a TD on the opening drive of the second half for Arizona.

“Obviously, we got to play a lot better,” coach Kyle Shanahan said. “I talked to the defense a lot about some of the things that you guys saw out there. Offensively, I thought we had our opportunity. We just had to play and make those plays like we did last week. I thought it was there for us, especially in the first half and we didn’t get it done and it got us in the hole and we weren’t able to overcome it.”

Shanahan said the performance came as a surprise after the Niners played well last week in a 33-22 win at Chicago and had a good week of practice.

San Francisco then appeared to catch a break with the Cardinals playing without Murray and his top two wideouts, but it didn’t help.

Shanahan said he warned the players not to have a letdown because of those injuries. The defense came out flat anyway.

“That’s something that I aggressively talked about last night,” he said. “For those guys to let down on it, I think it came down to, you guys saw how we tackled out there. We didn’t stop the run and we didn’t stop those screens. When you’re giving up some explosive screens and all of that free yardage, it wouldn’t of mattered who was playing quarterback. We made it extremely easy on them.”

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