It was clear from the outset on Sunday that the Cleveland Browns were going to need to move the ball on the ground. The Browns, to their credit, dialed it up.

They used misdirection, motion, a variety of blocking schemes, leaning on Kareem Hunt and Jerome Ford without star offensive lineman Joel Bitonio. This was the plan with P.J. Walker making his first start of the season in place of the injured Deshaun Watson.

The 49ers allowed 160 yards and a touchdown on the ground over 30 carries, for a 4.7-yard-per carry average.

By any assessment, it was a woeful defensive performance against the ground game. Kyle Shanahan made that clear on Monday, when asked about what he thought.

“I was disappointed in it,” Shanahan said. “I’m not sure the exact stats compared to others, but if I had to guess, it was our most missed tackles on the year. I thought they got our edges way too much, blocking down our D-ends and getting around.”

He singled out the fact that the 49ers played a lot of Cover-2. In the past, he said they’ve had little issue defending the run with that defense, but clearly had some gripes with the tactical approach, and seemed to suggest that with Walker quarterbacking, the defense should have sold out on the run a bit more.

“We played a lot more two-shell defense and when you play two-shell defense, you’re a little bit behind in the run game,” Shanahan said. “But we’ve been able to stop guys pretty good in that way and when they got our ends and we weren’t getting our safeties downhill, they bled us out too much.

“And when you add on a couple of those missed tackles and everything, it was way too much. Especially when you have a quarterback who’s coming in who hasn’t started yet, the best way to make that guy uncomfortable is to take away the run game and with 160 yards and that, we obviously didn’t. That was disappointing, especially on those last two drives.”

It’s not quite a cause for panic, but there have been moments this season that make it appear like defensive coordinator Steve Wilks is still adjusting to what the 49ers ask of him. At the very least, he seems to have a slower hand tendency towards in-game, in-drive adjustments.

He said earlier in the year that his tendency is to keep things simple and make adjustments as the game goes, but perhaps the 49ers will need a bit more proactivity in that department going forward. The lack of Dre Greenlaw on Sunday obviously made things quite a bit tougher.