EAST RUTHERFORD, N.J. — With their dismal performance on Sunday, the New York Giants defense officially sank to the bottom of the NFL.

The Giants, who on Sunday gave up 510 yards on offense in a 38-17 loss to the Seattle Seahawks, have allowed an average of 404.9 yards per game, the worst mark in the league.

So what has been behind the Giants defense’s downward spiral?

“I just wish it was one simple obstacle that I could point at,” linebacker Jameel McClain said. “We need to just play football. Play assignments. When you have to do something, do that. Sometime when you have to do your assignment, go a little bit above that. Make the play.”

It sounds simple enough, but the Giants had trouble carrying thought with it, particularly in the second half of the game where they had not one but two opportunities to recover a loose ball and snuff out a Seattle scoring drive.

Instead, they failed twice, their failures contributing to the Seahawks blowing the doors off the game with a 21-point fourth-quarter onslaught.

Perhaps the most alarming thing to come out of the Giants’ defensive meltdown on Sunday was how they were repeatedly gashed on the ground, giving up a total of 350 yards, the third-highest total allowed by the Giants on the ground in the franchise’s 90-year history..

That yardage included 140 yards by running back Marshawn Lynch and 107 yards by quarterback Russell Wilson, making them the first pair of Giants opponents to rush for at least 100 yards in the same game since Dec. 23, 2013, when Raves running backs Bernard Pierce and Ray Rice ran for 123 and 107 yards respectively.

“We just didn’t play sound football,” McClain said, stating the obvious. “People weren’t where they were supposed to be, myself included. I always look at myself first. There was a time or two where I wasn’t in the position that I was supposed to be in to help the defense. We really didn’t play solid football. That is it in a nutshell.”

That and the few wrinkles that McClain admitted caught the Giants off-guard.

“We were definitely prepared. Coach had a great game plan. The game changes. There always will be a few surprises. We can’t predict exactly what they are going to do. They did have a few wrinkles that we did not know of. Within those wrinkles, they got some plays off it. All in all, it is just a player thing. Us players, myself as a player, we need to play better.”

The mention of the unexpected wrinkles run by Seattle raised a few eyebrows and prompted the question of how well the defensive coaching staff was prepared to be asked of head coach Tom Coughlin.

“I do think that they worked as hard as they possibly could. I think we took every moment of jog-through and practice time and saw the option, the dive, and the quarterback from many different circumstances, from different formations, etc.,” he said.

“I don’t think we executed it very well, and we needed to make sure that when you have something as important as to their style of attack as that particular keeper and option are, that you have to spend all of your time doing that and you can’t assume that anyone understands everything. You have to stay on that and harp on that. Sometimes, to be honest, you do that at the expense of other things.”

Now comes the million-dollar question: Can the banged up Giants defense fix what has been a recurring trend over the last month and get things back on track?

“Absolutely, it is fixable,” McClain said. “It is more communication. It is more attention to detail. It is more [if someone doesn’t know], ask a question. It is more of that. Everything can be fixed.

“In these past weeks, we haven’t done well, so this is the time the iron strikes and it is hot. We get it rolling the way it is supposed to be going. People really have to look at themselves–starting with me, I have to look at myself harder and see what I can do better.”