The San Francisco 49ers know exactly what kind of challenge is coming Sunday. It's not just about stopping Miami Dolphins RB De'Von Achane. It's not just about containing QB Malik Willis. It's about making sure neither one of them gets loose.
Speaking with NBC Sports Bay Area's Matt Maiocco, Kyle Shanahan discussed the problems Miami's two most dangerous rushing threats can create for a defense. And when Shanahan talked about Achane, it was clear the Dolphins running back made an even bigger impression on him than expected. But don't count out Willis either. "Those guys right there, I mean, anytime you have a running quarterback who has the ability to run, it always causes problems for our defense," Shanahan said. "We have to make sure you can't fall asleep on them."
Willis presents a specific problem because of what he can do with his legs. The former Titans and Packers quarterback can turn what looks like a normal pass play into a problem for the defense by taking off. That puts additional pressure on every defender to do his job because one missed assignment can turn into an easy first down.
"How you rush them, how you play each run play, you never know when he's gonna pull it and go," Shanahan told Maiocco. "And it's a very cheap, easy way to get first downs. It's a very easy way to get points and keep people on the field."
That's where Achane comes in. If Willis can consistently pick up yards when defenses aren't accounting for him, it creates more opportunities for Miami's explosive running back. "And when a quarterback can do that and get some easy first downs just not being accounted for, and you get more plays for a guy like Achane, that can be trouble," Shanahan added.
Achane doesn't need many opportunities to change a game. He rushed for 1,350 yards on 238 carries last season, averaging 5.7 yards per attempt, while adding another 488 yards receiving (1,838 yards from scrimmage).
But Shanahan's biggest concern isn't necessarily how much yardage Achane can accumulate in the game. It's how quickly he can get it. "Just watching him this week, I knew he was good, I knew he was really good," Shanahan said. "But he's even better than I thought."
The 49ers head coach then pointed to the number that apparently caught his attention during his film study. "Just watching the amount of big plays he can make. I think the stat they gave me: 15% of every time he touches the ball, he had an explosive last year, which was by far number one in the NFL."
That explosive-play ability is what makes Achane so dangerous. In 2025, he had 13 rushing plays of at least 20 yards and four of at least 40 yards. His longest run went for 59 yards.
And Shanahan doesn't believe a game situation necessarily makes Achane less dangerous. In fact, he offered a pretty good warning to his defense. "If you're sitting there up two scores and there's four minutes left, you better not feel comfortable," Shanahan said. "Cause he can score like that if you're not on him."
The 49ers can't afford to let Willis pick up easy yards with his legs. They can't afford to lose track of Achane. And they certainly can't let Willis extend drives to create additional opportunities for Miami's biggest playmaker. Shanahan summed it up, saying, "That's why you can never fall asleep on either of those guys."
For a 49ers defense that looked strong in its season-opening win over the Rams, week two will present a different kind of test. The Dolphins have the quarterback to make a defense account for an extra runner on virtually every play. They have a running back capable of turning one missed assignment into six points.
Shanahan understands the problem. Now the 49ers have to make sure they don't fall asleep.
Watch Maiocco's full interview with Shanahan below:
Comments