SANTA CLARA, Calif. – A few thoughts on the Arizona Cardinals’ 20-17 loss to the San Francisco 49ers on Sunday at Levi’s Stadium:

What it means: Cardinals quarterback Ryan Lindley made coach Bruce Arians look pretty smart Sunday afternoon. After initially deciding to start rookie Logan Thomas, Arians reverted back to Lindley midweek, and Lindley rewarded the Cardinals with a career-high 316 yards on 23-of-39 passing with his first two career touchdown passes and an impressive performance, despite three interceptions (one of which was quite costly). But for as well as Lindley played, the Cardinals’ defense didn’t give the type of effort needed for Arizona to win with a third-string quarterback. The defense missed too many tackles and, as with Seattle’s Russell Wilson a week ago, couldn’t contain San Francisco quarterback Colin Kaepernick, especially up the middle. Arizona gave up 206 yards rushing. Maybe the most impressive part of Sunday’s game was watching Arians alter his play-calling a week after deep throws and getting away from the win got Arizona beat badly. He put Lindley in position to win, but the defense didn’t help the cause.

Stock watch: Michael Floyd went more than three months without a 100-yard game, but he had that in the first half Sunday. Floyd finished with 153 yards and two touchdowns while tying his career-high with eight catches. It was the second game of the season in which Floyd had two touchdown receptions.

Missing Foote: After missing just one snap this season, linebacker Larry Foote missed his first game of the season on Sunday, and his absence was noticeable. The combination of Kevin Minter and Glenn Carson filled in for Foote at inside linebacker, but their inexperience was evident at times, as they were lured away from the center of the field, and Kaepernick took advantage by bolting up the middle for 45 yards on two runs in the third quarter.

Game ball: He was the Cardinals big-ticket signing in free agency back in March, and left tackle Jared Veldheer lived up to all the hype that came with becoming the cornerstone of Arizona’s offensive line. The Cardinals have allowed 26 sacks this season -- 15 fewer than last season. Veldheer, the team's MVP, was responsible for just one of them.

What’s next: Arizona will play at Carolina next weekend in an NFC wild-card playoff game.