Seahawks’ ‘Legion of Boom’ backfield will be a big test for the Rams’ thriving offense

The Seattle Seahawks “Legion of Boom” defensive backfield has been making it tough on NFL quarterbacks and receivers for more than half a decade.

Cornerback Richard Sherman and safeties Kam Chancellor and Earl Thomas are mainstays, and cornerback Jeremy Lane the latest to fill the role opposite Sherman.

The quartet — along with an aggressive front seven led by end Michael Bennett and linebacker Bobby Wagner — is expected to give Rams’ quarterback Jared Goff and coach/play-caller Sean McVay their toughest challenge yet on Sunday at the Coliseum.

“It’s going to be a great measuring stick for our offense,” offensive coordinator Matt LaFleur said Friday.

Goff struggled against the Seahawks last season in a 24-3 defeat at CenturyLink Field, a game that was played three days after the Rams fired Jeff Fisher as coach. During the loss, Sherman leveled Goff on a scramble along the sideline.

But Goff has progressed under the tutelage of McVay, LaFleur and quarterbacks coach Greg Olson. New left tackle Andrew Whitworth has protected Goff, and running back Todd Gurley and receivers Sammy Watkins, Robert Woods, Cooper Kupp and others have provided dependable targets for the second-year quarterback.

Goff has passed for seven touchdowns, with only one interception.

The Seahawks secondary is capable of ruining that efficiency.

Thomas is a five-time Pro Bowl selection. Sherman and Chancellor made the Pro Bowl four times.

The continuity is apparent in a veteran unit that ranks fourth in the NFL in passing defense.

“A lot of it starts with Earl Thomas,” LaFleur said. “He’s a guy that, on the back end, he’s all over the place and he plays with his hair on fire.

“They’re so good at diagnosing plays and then just teeing off on whatever they see.”

Happy return

Pharoh Cooper is eager to build on last week’s 66-yard kickoff return against the Dallas Cowboys.

“Looking forward to breaking some more,” the second-year receiver said.

Cooper’s play came a week after he fumbled late in the game against the San Francisco 49ers.

McVay was pleased with the way Cooper responded to the miscue. He also said he was confident that Cooper would come through at receiver if more opportunities on offense present themselves.

Cooper backs up Woods, and has one catch for four yards.

Cooper would welcome more opportunities on offense.

“I love kick-returning — it’s my role for right now on this team and I’m going to do whatever it takes,” Cooper said. “But I’m never going to lose sight of the fact that I’m still ready to burst onto the scene as a receiver in this league.”

Etc.

Jamon Brown (groin) was limited and is questionable for Sunday’s game. Safety Lamarcus Joyner (hamstring) is doubtful. Seahawks defensive ends Cliff Avril (neck) and Quinton Jefferson (hand) have been ruled out for Sunday’s game.

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