Cardinals running back David Johnson could be relied on heavily against the 49ers.

SANTA CLARA, Calif. – The bandwagon is thinning and the complaints are rising.

A Cardinals team expected to be one of the best in the NFL has looked anything but through four games, dropping to the NFC West cellar after a third loss on Sunday to the Rams.

The Cardinals didn't lose four regular season games at all in 2015 and won 11 before doing so in 2014. They hope to avoid hitting that ignominious mark in this Thursday Night football affair against the 49ers, and will be playing without quarterback Carson Palmer because of a concussion.

A team expected to cruise to the playoffs is already in danger of skidding uncomfortably far off track, and while the players profess they aren't panicking, there is certainly urgency.

"We understand we have a lot of football left in front of us, but if we're going to make our push, we've got to do it right now," wide receiver Larry Fitzgerald said.

If you hear some players tell it, the weight of expectations early may have been a burden. After such a fantastic 2015, a deep playoff run was practically penciled in before this year's opener.

A month later, the Cardinals have been labeled one of the most disappointing teams in the NFL.

"Everybody that believed in us, they don't believe in us no more," safety Tyrann Mathieu said. "It's just us now. We prefer that."

Whether buoyed by motivation or better execution, the Cardinals need to find a way scratch out a win against San Francisco. Much could depend on the play of backup quarterback Drew Stanton.

He went 5-3 in place of Palmer in 2014, but has been poor in spot duty the past two seasons. He was just 4-of-11 for 37 yards with two interceptions while trying to lead a game-winning drive against the Rams on Sunday.

The 49ers (1-3) are certainly no juggernaut, as they are 28th in the NFL in total offense and last in run defense. The Cardinals figure to lean on running back David Johnson, but at some point, Stanton will be asked to make some throws.

49ers coach Chip Kelly doesn't expect a watered-down offense from the Cardinals after watching tape of Stanton's appearances two years ago.

"You really have to defend it all," Kelly said. "It's not like when Drew's in, they're going to do this; when Carson's in, they're going to do that. Because when both those guys are in, in their past history, they've done everything."

Even though the Cardinals are 1-3, all hope is not lost. They have a plus-12 point differential on the season, a defense which is playing well, and the talent to get it turned around. But the margin for error is already small, and it would shrink to razor thin with a 1-4 start.

"It's not like we're going into games and getting our brains beaten in," offensive coordinator Harold Goodwin said. "We've just got to make sure we're executing through all four quarters, especially at the end."

Physically, the Cardinals would prefer waiting the standard week to play again. Cornerback Patrick Peterson said his legs felt heavy until Wednesday, and now he will be right back on the field.

But mentally, it might be good to put the Rams loss and the first four games behind them quickly.

"You don't have a choice but to get past it," coach Bruce Arians said. "If it were a normal week, they could brood until they showed up Wednesday."

The Cardinals will have 10 days between this game and a "Monday Night Football" matchup next week against the Jets. If they lose, it could be a miserable week-and-a-half. If they win, it could be viewed as the first step in a return to normalcy.

A Week 5 road game in San Francisco wasn't supposed to mean this much, but the team knows the stakes.

"This is not the start that we all anticipated, obviously, but this is what it is," Fitzgerald said. "We are who we are. Now, if we want to change it, we have to take it upon ourselves and make it happen."