SANTA CLARA, Calif. -- Looking back at how the San Francisco 49ers fared in three key areas of Sunday's 20-10 loss to the Arizona Cardinals.

Digging deep

The 49ers' injury report last week was so long that it was almost faster to name the players who aren't on it than those who are. The Niners listed 14 players on their practice reports early in the week.

Among those who ruled out against Arizona before the game even started were left tackle Joe Staley (eye), defensive end Solomon Thomas (knee), free safety Jimmie Ward (on injured reserve with a fractured arm), receiver Pierre Garcon (also on injured reserve with a neck issue), cornerback K'Waun Williams (quadricep), defensive end Aaron Lynch (calf) and tackle Garry Gilliam (knee).

The Niners were going to have to dig deep into their depth chart in order to have a chance to extract revenge against the Cardinals. That means leaning on players who have only recently been brought on board. Lesser-known players like defensive lineman Leger Douzable, cornerback Greg Mabin and linebacker Mark Nzeocha are just a few of the players who could be asked to take on bigger roles.

Alas, the injury bug did not go away as the Niners lost even more key players throughout Sunday's game. Safety Jaquiski Tartt (broken arm), fullback Kyle Juszczyk (neck), receiver Trent Taylor (ribs), linebacker Elijah Lee (knee) and tight end Cole Hikutini (knee) all departed the game and did not return.

No surprise, all of that was simply too much to overcome for the Niners, who simply couldn't squeeze enough from the bottom of their roster to get the job done.

Whither Garoppolo?

There was no bigger story in the NFL last week than the 49ers' bold move to trade for quarterback Jimmy Garoppolo. Of course, the next question is when Garoppolo will make his debut.

Coach Kyle Shanahan has already said that rookie C.J. Beathard will continue to start at quarterback, and that was the plan against Arizona. Meanwhile, there remains no definitive plan to get Garoppolo in.

However, with the aforementioned injuries piling up, the Niners didn't have the luxury of carrying a third quarterback on the active roster right now, which meant Garoppolo had to serve as Beathard's backup less than a full week after arriving in the Bay Area. Shanahan said during the week that he doesn't plan to put Garoppolo in unless Beathard suffered an injury, but behind an offensive line without Staley and some other pieces, Beathard could find himself in peril on a consistent basis.

That's exactly how it played out, as Beathard was sacked five times and hit a total of 16 times during the course of the game. Those hits and Beathard's resulting struggles never resulted in Garoppolo entering the game, however. Shanahan said after that he never considered switching to Garoppolo and pointed out that Beathard's day was through little of his own doing.

It didn't help the 49ers on the scoreboard but in the big picture, Beathard's toughness paid dividends as it allowed the Niners to keep Garoppolo under wraps in his first week with the team.

Sacking Stanton

Of course, the Niners weren't the only team in Sunday's game dealing with important injuries on offense. Arizona was missing quarterback Carson Palmer, who suffered a broken arm against the Los Angeles Rams in London. Palmer, who threw for 357 yards and the game-winning touchdown in the first meeting, was replaced by veteran backup Drew Stanton.

Stanton hadn't played much in his career but entered the week 2-0 against the 49ers, including a win at Levi's Stadium last season. Like Beathard, Stanton was working behind an offensive line that hadn't been all that productive even when healthy. The Niners sacked Palmer six times and hit him a whopping 16 times in that first meeting.

While Stanton isn't exactly a threat to run, he is more mobile than Palmer, which should help him avoid taking so many hits this time. As it turned out, that's exactly how it played out and it made a difference in the game.

The Niners hit Stanton seven times but registered zero sacks as he used his legs to escape pressure multiple times and make some big plays. Stanton's numbers didn't wow anyone but he finished 15-of-30 for 201 yards and two touchdowns with an interception for a passer rating of 80.0. It wasn't awe-inspiring but Stanton's ability to avoid pressure was enough to out-perform Beathard and leave the Niners winless in their first nine games.