The Seattle Seahawks are struggling to survive in an NFC West division that has three of four teams below .500 nine games into in 2015.

One reason may be that one of their strengths during the dominant 2013-14 seasons—their secondary—has now faded, and isn't what it once was.

The defensive backfield, also known as The Legion of Boom, has been a shadow of its former self, as far as intimidation, generating turnovers and creating momentum-changing plays.

All-Pro safety Earl Thomas confirmed this on Thursday.

When asked about The Legion of Boom, and if the chemistry is what it once was, Thomas replied, "Of course not," according to the Seattle Times.

[MAIOCCO: Sherman turns attention to Smith after years of facing Crabtree]

Why not?

"I just think it's an attitude, it's a mindset," Thomas added. "You've got to give it up for the next guy. It's not showing up all the time like that."

But why has the attitude that made them so successful changed? Thomas said, “I couldn’t tell you. Just people got to get out of their own way and give it up for the team."

The Seahawks have lost pieces over the past couple years. Former starting cornerback Brandon Browner has had stints with the New England Patriots and the New Orleans Saints since Seattle last won a Super Bowl.

Walter Thurmond and Byron Maxwell have also moved on, now with the Philadelphia Eagles. Safety Kam Chancellor missed time early in the season due to a holdout. Former defensive coordinator Dan Quinn is now the head coach of the Atlanta Falcons.

And in last week's loss to the Arizona Cardinals, quarterback Carson Palmer targeted All-Pro cornerback Richard Sherman often, and finished 5-for-8 for 67 yards and a touchdown, according to Pro Football Focus.

The Seahawks (4-5) are fresh off a loss, and have dropped three of their last five games. Their four interceptions are tied for last in the NFL (T-Baltimore, New Orleans and Detroit).

They still have the No. 2-rated pass defense and total defense in the league entering Week 11. Seattle on Sunday hosts Blaine Gabbert and the rival 49ers (3-6).