Familiar failings ruin a career day for Jauan Jennings as 49ers lose to Rams in brutal fourth-quarter collapse

Put simply, the 49ers were too easily pushed off the ball in the run game and made it too easy for Stafford to find explosives in the pass game despite the absence of Cooper Kupp and Puka Nacua. 

Defensive end Nick Bosa summed it up succinctly.

"Plenty of opportunities," said Bosa. "It wasn't good enough, we've got to close them out when we have a chance."

Personnel issues on both sides of the ball were a huge contributing factor to the 49ers' inability to close out a game they had in their grasp.

Personnel changes must be made

The tape review session for the 49ers on Monday will not be an easy one, especially for several players who deserve to be worrying about quickly losing snaps.

On the defensive side of the ball, De'Vondre Campbell was continually victimised in coverage and gave up a crucial pass interference penalty after the Rams' key punt return that put them in prime field goal range.

Campbell was supposed to be a dependable placeholder while Dre Greenlaw recovered from the torn Achilles he suffered in Super Bowl 58. So far, he is proving anything but.

Worse was corner Isaac Yiadom, who had no answer for Rams receiver Tutu Atwell. After giving up three first downs on third down on a key fourth-quarter drive in the Vikings loss, Yiadom was once again porous in coverage having been signed as a player on whom the 49ers believed they could rely to play outside corner on nickel downs when Deommodore Lenoir kicks inside.

With younger alternatives waiting in the wings, the 49ers need to be honest about the lack of production they are getting from supposedly reliable veterans. Changes that see Dee Winters come in at WILL linebacker for Campbell and rookie second-round pick Renardo Green take over for Yiadom at corner must be considered.

On the other side of the ball, there should be greater scrutiny on Colton McKivitz's position as the starting right tackle after he gave up a sack on which Purdy was stripped of the ball at the end of the first half with the 49ers on the edge of field goal range. The 49ers have tried to paper over the right tackle issue for two offseasons now, and it is still a glaring problem on the offensive line.

More importantly, though, the 49ers cannot ignore the blatantly obvious on offense, which is that giving Ronnie Bell snaps over fourth-round rookie Jacob Cowing is malpractice.

Bell had the game in his hands after Los Angeles had tied it at 24-24 on a perfect deep ball from Purdy, yet he committed a key drop that marked his second of the game and allowed the Rams' pass rush to pin its ears back on third down and force that fateful punt.

Speedy preseason star Cowing has yet to play an offensive snap for the 49ers. If the 49ers had their full complement of pass-catchers, it's unlikely that Bell would have been on the field, yet the fact he was favored over Cowing throughout what was a golden opportunity to get a potentially dynamic rookie on the field represents a complete misevaluation of the personnel the 49ers had at their disposal.

Asked about the decision to go with Bell, Shanahan replied: "Ronnie's been having a hell of a camp, a hell of a week of practice, but he's got to come down with the catch."

The fact he didn't spoiled what should have been a day of celebration for the 49ers and particularly the ultra-reliable Jennings. This is a loss that needs to spark a 'come to Jesus' moment in the 49er facility about several players on whom they are relying too much. If it doesn't theirs may be a Super Bowl hangover that lingers for a long time.