"Terrible, without question," Suh said, adding later, "That's my personal opinion... It's terrible just from a standpoint of how much run yardage we gave up."
In Week 4 the Minnesota Vikings rushed for 54 yards, including 28 by Kirk Cousins.
"I can't think back to many times to defenses that I've been a part of that have been [at] 191 yards, let alone many times over 100...I've been a part of some great defenses where we've, in a year, not allowed but maybe one team to get close to 100 or over 100," Suh said. "So that's what I pride myself on and want to maintain that and we have all the tools to be able to be that type of defense."
The Rams made several trades and spent a significant amount of money over the offseason to upgrade their defense.
They acquired All-Pro cornerbacks Marcus Peters and Aqib Talib, signed Suh to a one-year, $14 million contract and awarded reigning NFL Defensive Player of the Year Aaron Donald with a six-year, $135 million extension.
Defensive coordinator Wade Phillips said Thursday that he emphasized assignment-sound football in his signature 3-4 scheme.
"We just tell them, 'Hey, play the defense called. Don't play 3-4 on your own,'" Phillips said. "Guys want to make plays. You've got to trust the guys on your team. You've got to trust the calls and trust the guys on your team. If everybody does their job, then you can do yours better."
In the first two games of the season, the defense posted six consecutive shutout quarters, including a 34-0 shutout over the Arizona Cardinals.
Through 5 games, the Rams have the 10th-ranked total defense, but are ranked 18th against the run, allowing an average of 106.8 yards per game and 5 yards per carry.
Against the Seahawks, Donald said some players were trying to do too much.
"We've got to play better in certain situations," Donald said. "Just might be out of our gap here and there and then you get hit and they hurt you, so it's just little mistakes, things we need to fix, man, and we just got to keep working."
Suh said the young running backs would present a challenge, but expected an improved performance if the Rams returned to fundamentals.
"We just got to be consistent, that's what it's going to come down to," Suh said. "When we get consistent, when we're all on the same page, it will be a dangerous defense."