I can see this happening. In week 11 the Rams only put up 249 yards, which is the norm for this defense. The only teams to score more that 21 points on us this year were the Bucs on an injury filled week, the Rams in week 16, and the Cards (22) and Titans (24), both getting garbage time TDs.
In week 16, the Rams put up a whopping 581 yards on a massive day by Stafford (457) and Nacua (225), but Mike McDonald took the blame for the poor defensive showing saying that he tried to put too much in on a short week which led to confusion and blown coverages in the secondary.
Given that the defense has given up 19 points in the 3 games since then -- 10 to the Panthers who put up 31 on the Rams in the wildcard, and 3+6 over two games to the 49ers who had put up 42 on the Bears the week before us and 23 on the Eagles in the wildcard round -- I would say our defense is improved since week 11 and week 16 was an outlier.
If I was a Rams fan, I'd be worried. They barely won a 4 INT game week 11, and then got taken to OT and beat on our worst defensive outing of the season in week 16. If the Seahawks just play to their average on offense and defense, the Rams may get blown out.