SANTA CLARA – Things could not have gone much worse for the 49ers on Sunday, and they now run the risk of seeing their season quickly fall apart.
Their top running back exited in the first quarter with an ankle injury. The 49ers committed five costly turnovers and did not generate any takeaways in return. And even their ultra-reliable kicker also had one of those days.
Robbie Gould and the field-goal unit aborted an extra-point attempt in the first quarter. Later, Gould's streak of consecutive field goals ended at 33 when he pushed a 45-yarder wide.
The previously winless Arizona Cardinals took advantage of a lot of 49ers mistakes for a 28-18 victory at Levi's Stadium, giving first-year head coach Steve Wilks his first victory.
It was Arizona's seventh consecutive victory over the 49ers, who fall to 1-4 on the season.
Here are three takeaways Sunday's game:
Lacking in passing game
Coach Kyle Shanahan schemed up the first drive of the game with a plethora of short passes to slow down the Cardinals' blitzes. But after the Arizona made the adjustment, the 49ers did not have enough firepower on offense to create much of a threat.
Marquise Goodwin was inactive with hamstring and thigh issues. His backup, Dante Pettis, did not suit up due to a knee injury. The 49ers were lacking speed on the outside, which is a requirement for Shanahan's offense. Rookie Richie James made his first career start after being inactive for three of the first four games. He caught one pass for 7 yards.
Moreover, Pierre Garcon sustained a shoulder injury in the first quarter. He returned before the end of the first half, but was largely ineffective. Quarterback C.J. Beathard did not get much help from Garcon, who had a deep in-route deflect off his hands for a first-quarter interception.
Beathard completed 34 of 54 passes for a career-high 348 yards with two TDs and two interceptions. He was sacked four times and lost two fumbles.
Secondary ups and downs
Richard Sherman was back in the starting lineup after missing just 1 ½ games with a mid-calf strain. But it's the play on the other side that is the much greater concern.
It did not take Cardinals rookie quarterback Josh Rosen long to exploit the 49ers' play at right cornerback.
On the opening play of Arizona's first drive after the 49ers took a 6-0 lead, Christian Kirk beat Ahkello Witherspoon deep. Free safety Adrian Colbert, who was playing the deep middle, ran up and allowed the pass to sail over his head for a 75-yard touchdown. Greg Mabin rotated into the game with Witherspoon, while Sherman played the entire game on the other side.
After the first play, the 49ers' defense played well enough to win, as the pass defense tightened up. Rosen completed just 10 of 25 pass attempts for 170 yards with one touchdown and no interceptions.
Help needed at running back
The 49ers have been preparing to add a running back in recent weeks with Matt Breida and Alfred Morris experiencing some injury concerns. That time might be now.
Breida sustained a left ankle injury in the first quarter and did not return. He underwent X-rays, which were negative, according to a source. The 49ers are hopeful that he will be able to play next Monday night against the Green Bay Packers. Breida's presence was sorely missed. He had 56 yards rushing on eight carries before the injury.
Raheem Mostert entered the game after Breida's injury and fumbled on his first rushing attempt. Patrick Peterson picked up the loose ball and returned it 49 yards to set up the Cardinals' second touchdown.
Morris rushed for a game-high 61 yards on 18 rushing attempts.
The 49ers could look outside the organization or promote undrafted rookie Jeff Wilson from the practice squad.