What can stop the Seahawks in the NFC playoffs?

SEATTLE -- Seattle Seahawks center Patrick Lewis sat at his locker in full uniform Sunday evening as his teammates shuffled to and from the showers.

He folded his hands and stared at the floor in front of him. This was a bad day at the office for the veteran. Lewis had several errant snaps during the team's 23-17 loss to the St. Louis Rams. Russell Wilson was sacked four times and hit on 13 of his dropbacks. The two primary running backs -- Christine Michael and Bryce Brown -- totaled 15 yards on 13 carries.

Lewis clearly was disappointed in his own play and the loss, but some of his teammates seemed to take the defeat with a grain of salt. The Seahawks have already clinched a playoff berth, and given some of the losses they've suffered in the past couple years, this one didn't rank too high on the devastation scale.

Having said that, the focus will soon be on the playoffs, and the only question that really matters is: Can this team make a run? The Seahawks will take on the Arizona Cardinals in Week 17 and won't know their first-round opponent until Sunday night. But we now have a 15-game sample size of their strengths and weaknesses and what will determine whether they reach the Super Bowl for the third straight year.

Given what we saw Sunday and how this season has played out, below is a look at the three things that could prevent them coming out of the NFC.

1. Offensive line issues

The loss to the Rams was a reminder that the cliche about it all starting up front really rings true with this group. The Seahawks' offense has been at its best when Wilson has had time to operate from the pocket. During the five-game winning streak, they mixed in a quick passing game with a solid rushing attack, play-action and shot plays.

But if the offensive line doesn't win its battles, major issues surface and the Seahawks rely too much on Wilson improvising and connecting on big plays. Against the Rams, he was constantly on the run and the offense never found a rhythm.

Among potential opponents in the NFC, the Carolina Panthers and Arizona Cardinals have the best overall defenses. The Green Bay Packers have produced sacks on 6.6 percent of their opponents' dropbacks, fifth-best in the NFL. The Cardinals have been good against the run. And Carolina probably has the top group overall.

The Seahawks have been very good offensively this year. But if they struggle to score points in the postseason, it will be because of issues on the offensive line.

2. Facing a prolific passing attack

Case Keenum threw for only 103 yards. He wasn't the reason the Seahawks lost Sunday. But earlier in the season, the Seahawks had issues against quarterbacks like Arizona's Carson Palmer and Pittsburgh's Ben Roethlisberger. Green Bay's Aaron Rodgers had success against the Hawks' defense, and Carolina's Cam Newton put together three drives of 80 yards in the fourth quarter vs. Seattle.

Overall, the defensive statistics for the Seahawks are impressive, but there are some holes that can be exploited. According to ESPN Stats & Information research, the Seahawks have allowed seven touchdowns of 25-plus (air) yards on the season. That's third-most in the NFL and the most they've allowed in a season since 2008.

The teams that are getting high-level quarterback play and know how to attack the Seahawks' coverages are the ones most likely to give them problems. Even though the Packers are not playing great, the Seahawks would probably be best served to avoid Rodgers in the first round. And their worst matchup in the NFC is likely Arizona.

3. Not getting enough from the run game

There's no doubt this team would look different with Thomas Rawls. Carroll indicated Sunday that the issues in the run game vs. the Rams were more on the offensive line than the running backs. But right now, the Seahawks are playing two guys in Brown and Michael who weren't even on a 53-man roster a couple weeks ago.

The X-factor here, of course, is Marshawn Lynch. It's probably a waste of time attempting to predict what he's going to do, but we know Lynch has been rehabbing in the Bay Area from surgery associated with a sports hernia injury. Carroll could not say for sure whether Lynch will return to practice this week.

Would he need touches against the Cardinals to see how he feels before the postseason? Can he jump right into a playoff game and look like his old self? Is there a chance he doesn't come back at all?

These questions need answers in the coming weeks, and they'll go a long way in determining how far this team can go.