Some early warning signs came in the 2011 postseason as the Ravens started allowing lots of rushing yards. Maybe it was an aberration, but it has to be a concern heading into the second week of training camp.
For nearly a decade, the Ravens had a top-ranked rush defense and allowed few teams more than 100 yards on the ground. Allowing 100-yard rushers occurred even less frequently.
Then, in the last three games of the 2011 regular season, San Diego, Cleveland and Cincinnati each gained more than 100 yards rushing.
Houston running back Arian Foster had 132 rushing yards against the Ravens in a second-round playoff game, and if the Texans had quarterback Matt Schaub, the Ravens likely wouldn't have made it to the AFC championship game, where they gave up 96 yards rushing in a 23-20 loss to New England.
This wouldn't be a big deal in the past because the Ravens always had defensive linemen like Tony Siragusa, Sam Adams and Haloti Ngata, as well as a 260-pound monster linebacker in the middle named Ray Lewis, and good support guys on the outside like linebackers Jamie Sharper, Terrell Suggs and Jarret Johnson.
But some of those guys have retired and Lewis has become the incredible shrinking player. Suggs is out indefinitely with a torn Achilles tendon, Ngata has a bad hamstring and the Ravens have several unproven players now in starting roles.
Yes, there is some concern because the Ravens used to go into every game knowing they can stop the run, but they have to prove it this year.
Lewis and fellow starting linebacker Jameel McClain said they lost weight to keep pace with a league that has gone pass happy, but that's not true about their own division, the AFC North.
The Ravens have struggled against the Bengals in recent years, mostly because they couldn't stop Cincinnati running back Cedric Benson.
Pittsburgh wanted to go back to a strong running game this season, so they hired new offensive coordinator Todd Haley, and drafted Stanford guard David DeCastro in the first round and Ohio State left tackle Mike Adams in the second.
Cleveland certainly is going to put the ball in the hands of rookie running back Trent Richardson, the former Alabama star who was the No. 3 overall pick in the draft.
So, there is something fishy about this weight loss stuff. It doesn't pass the smell test.
"It wasn't me encouraging him," Ravens defensive coordinator Dean Pees said. "That was something that he and Jameel both did. It wasn't my idea, it was their idea, but I also agreed with it. I thought it was a good idea."
We'll see about that, especially late in the season when a lot of players wear down. That may have happened to some of the team's defensive linemen last year. Ngata was having perhaps the best season of his career, but wasn't a factor in the postseason. Neither was nose guard Terrence Cody, who also had a strong start.
One of the team's most consistent linemen was defensive end Cory Redding, who had 43 tackles, but is now with Indianapolis. The Ravens are hoping third-year player Arthur Jones, who is having a strong camp, can replace Redding.
Cody appears to be in great shape and the Ravens aren't sweating Ngata's hamstring injury.
"It's not a major hamstring [injury], but Haloti has been around a long time," said Ravens coach John Harbaugh. "We'll bring him back when the time is right here. It won't be real long, but it's going to be a few days."
At least the Ravens will get Ngata back on the field, but it will be hard replacing Suggs and Johnson. Suggs is known as a pass rusher, but underrated against the run. He was fifth on the team in tackles with 70 last year and big enough to handle most tight ends.
There are few players as mean, ornery and relentless as Johnson. He didn't care about fame and graded out high in just about every game the past two seasons. He had 56 tackles a year ago despite playing on the strong side consistently during running plays.
The Ravens' top two candidates to start at outside linebacker are rookie Courtney Upshaw and fourth-year player Paul Kruger. Upshaw is going to make his share of rookie mistakes, and Kruger was regarded as a pass-rushing specialist coming out of Utah.
But now it's time for Kruger to show that he is an every down player.
"Just that — being an every-down guy [and] the responsibility that goes with that," said Harbaugh of Kruger's biggest challenge. "You've got to understand the whole game plan, you've got to know the defense, and you've got to know the base package and all elements of the sub package. Before, he was more of a part-time player, just had to know part of the package. I don't think he'll have a problem with the run. He's a very physical guy. The mental part of it, he's worked hard at it. He looks good."
At this point, everything looks good. Things looked good for most of last season, too, but the run defense struggled down the stretch. Maybe it was an aberration, but when you give up 21 more yards a game in the postseason compared to a 92.6 yards per game average in the regular season, there is a cause for some concern — even if it is in the pass happy NFL.