SANTA CLARA -- Defensive coordinator Robert Saleh chose an odd time to not have anyone cover Arizona Cardinals wide receiver DeAndre Hopkins.
Hopkins ran wide open across the field against the 49ers, who were trying to protect a three-point lead with less than six minutes remaining in the season opener on Sunday.
Of course, that was not the intention, as cornerback Richard Sherman revealed following the 49ers’ 24-20 loss in front of an otherwise empty Levi’s Stadium.
“There was a miscommunication on both sides,” Sherman said. “It was just one of those things we have to address. The calls didn’t get all the way through to everyone. We had two sides playing two different coverages.
"So any time you have that, there’s going to be a hole.”
Hopkins shook free on a crossing route to catch a short pass from Cardinals quarterback Kyler Murray. Then, he turned upfield and gained 26 yards after the catch before safety Jaquiski Tartt brought him down at the 1-yard line.
One play later, the Cardinals scored the winning points on Kenyan Drake’s touchdown run.
“It just comes down to executing down the stretch,” Sherman said. “We got to knock the rust off of some things -- some communication things we have to do better. It was a great learning experience for everyone, and it will help us in the future.”
Not only did the 49ers have the top pass defense in the NFL last season, but no team in a decade gave up fewer than the 169.2 yards per game the 49ers yielded in 2019.
On Sunday, the 49ers surrendered 224 net passing yards to the Cardinals, and another 100 yards were allowed by their pass defense on plays during which Murray scrambled for big yardage.
In a departure from the past, Sherman saw a lot of action on the defense’s right side. After playing only 12 snaps all of last season on that side of the field, he lined up there 23 times on Sunday, according to NextGen Stats.
“I was playing to the open side, so wherever there was more field, that’s the side I was playing to,” Sherman said. “That was an adjustment Coach Saleh made.”
Saleh appears willing to add more wrinkles to the 49ers’ defensive scheme this season with all of the main contributors in the secondary returning.
It should be easier to communicate in the defensive backfield with no crowds at games, but Sherman said the unique atmosphere provided other complexities.
“It was different in terms of communicating with one another, and hearing their communications and being locked into that,” he said. “So it was a cat-and-mouse game when it came down to those plays.”