Mark Madden: Steelers run defense taking a hit without Devin Bush

When a team is undefeated, problems tend to be papered over. They’re mentally minimized. “What’s there to worry about? They’re 8-0.”

Such is the case with the Steelers defense.

There’s a lot to like about that defense. But there are a few things to worry about, too, and they mostly trickle down from the loss of inside linebacker Devin Bush.

Bush tore the ACL in his left knee Oct. 18 vs. Cleveland. He’s out for the season. Robert Spillane has made the most of his comparatively meager talent in the interim. New arrival Avery Williamson makes his Steelers debut Sunday and will further shore up that spot.

But Bush runs (ran) the 40-yard dash in 4.44 seconds. He plays sideline to sideline. Very few inside linebackers have speed like that. Spillane, Williamson and Vince Williams (the other starter at inside ‘backer) do not.

Bush wasn’t perfect, but his speed often covered up for his mistakes (and some made by others).

The effect of losing Bush is reminiscent of when Ryan Shazier sustained his spinal injury in 2017. That seems unrecognized, maybe because the long-term outlook for Bush isn’t as frightening.

After Shazier got hurt, the defense struggled ‘til Bush was drafted last year. The trickle down of Bush being unavailable makes everybody else on that unit play a bit different.

Given how much losing Shazier hurt, it’s amazing the Steelers didn’t have better depth at inside linebacker this time around. (They never fail to have a good backup guard, though.) But perhaps that’s unfair: No second-string inside ‘backer is going to run the 40 in 4.44.

Nose tackle Tyson Alualu and nickel back Mike Hilton have also been out, but that’s not long-term. Their return will help, but Bush’s absence still leaves a great big hole.

Dallas ran through that hole for 144 yards (4.6 yards per carry) this past Sunday, Baltimore for 265 yards (5.6 yards per carry) the week before. The harm wasn’t done by big-name backs, either: Dallas’ Ezekiel Elliott had just 51 yards on 18 carries. Mark Ingram didn’t play for Baltimore.

They say numbers don’t lie. But those surrounding the Steelers’ defense are contradictory.

Dallas had nine carries that got zero yards or went negative. But they also had six double-digit runs, including two of 20 yards. The Steelers do OK at the first level, but not after that.

The Steelers went big in an attempt to stop Dallas’ rushing attack, mostly eschewing use of the nickel and dime. They often used five outside linebackers. The result was only two sacks, mismatches like outside ‘backer T.J. Watt covering wide receiver CeeDee Lamb on Dallas’ lone touchdown — and the Cowboys still gashed the Steelers via the run.

The damage done by Dallas on the ground made the Steelers defense drop to ninth in the NFL against the run (102.8 yards per game). It’s sixth in total defense (317.4 yards), fifth in pass defense (214.6 yards) and fourth in scoring defense (20.1 points per game).

The defense is first in sacks with 32, second in takeaways with 16. It is, first and foremost, reliant on splash plays, and those have major impact.

But it can’t get off the field on third down, allowing a 44.2% conversion rate. That stands 20th in the NFL. The Steelers are 11th in red-zone defense, allowing touchdowns on 59% of opposition trips inside the 20.

It is a very good defense, but not as dominating as it once shaped up.

How can the shortcomings get fixed? They probably can’t.

The best bet is to maintain strengths: Keep getting sacks and takeaways and hope everything else gets a little bit better — and that third-down play gets a lot better.

Other stats cause worry, too. Ben Roethlisberger has completed 11 of 35 passes thrown 20 yards or longer. Is Roethlisberger’s deep ball still there?

If the negative numbers are inconsequential, the Steelers will keep winning.

But 8-0 isn’t the only thing that matters. Playoff wins are what matters most. Sans Bush, can that defense reasonably control an offense like Kansas City’s?