When former 49ers defensive coordinator Robert Saleh started drawing interest as a head coaching candidate following the 2020 NFL season, the immediate front-runner to replace him was San Francisco's inside linebackers coach, DeMeco Ryans.
So when the New York Jets named Saleh as their new head coach in January, the 49ers wasted little time tabbing Ryans as their next defensive coordinator.
After four seasons coaching the linebackers, Ryans made his debut as a defensive coordinator Sunday in the 49ers' 41-33 win over the Detroit Lions at Ford Field.
On Monday, Shanahan was asked by reporters if he had any feedback for Ryans based on what he saw after watching the film of the win.
“I think DeMeco would tell you the same thing, it’s not as much about tweaking things, it's about doing things better," Shanahan said on a conference call with reporters. "There was a number of things that we've done here for going into our fifth year in a row early in that game, especially those three runs up the middle. Just a couple of guys not being in the right gap and it wasn't one culprit. It was three different guys on three different plays. I think they had like 110 yards rushing and I think they got 60 something yards on three of the same play which were all very similar.
"You’ve got to tie 11 guys together to stop the run. And one guy gets out, it's going to get on [DB] Jimmie Ward real quick because that's the middle-third player. And you're just hoping he can save a touchdown. So, the three of those really hurt, just a couple of mistakes there at the end of the game that allowed them to get some quick points. But stuff that we've got to get better at it in terms of not making mistakes. And so, I'm real excited to get to practice on Wednesday with that stuff.”
While the 49ers' defense held up well in the first half, Lions running back Jamaal Williams gashed them for runs of 10 yards, 20 yards and seven yards in the first quarter. On the Lions' fourth drive of the game, D'Andre Swift broke out back-to-back runs of 16 and 15 yards. The Lions finished with 116 rushing yards on 24 carries.
In the fourth quarter, with the 49ers leading comfortably 41-17, the Lions made a valiant comeback attempt, scoring 16 unanswered points to cut the deficit to eight. San Francisco appeared to put the game on ice, but Deebo Samuel fumbled after picking up a first down.
Quarterback Jared Goff got the Lions down to the 49ers' 24-yard line, but Ryans' defense forced a turnover on downs to preserve the win.
Ryans and the 49ers came away victorious, but there clearly are areas that need to be addressed as the season progresses.