Mailbag: Where are national expectations for Lions defense?

ALLEN PARK, Mich. -- The Detroit Lions had their first real action of the 2016 season Friday night in a 30-17 win over the Pittsburgh Steelers in the preseason opener.

And it left a lot of questions, both about depth and what’s going on with the Lions’ offensive line. We hit on that in this week’s Lions mailbag.

To ask a question, use the hashtag #LionsMailbag on Twitter, email me at michael.rothstein@espn.com or ask me on my Facebook page. Mailbags will run on weekends this season.

Now, to your questions.

@mikerothstein: Laken Tomlinson hasn't had the best camp, but there's still a few weeks to go and the Lions are banking on his improvement. At this point, he seems to be locked in as the starter at left guard, and I thought he did a decent job in the preseason opener. That said, I admit I'm not an expert when it comes to offensive line play. If the Lions were to move away from Tomlinson, the two options they would probably turn to are veteran Geoff Schwartz and rookie Joe Dahl. Schwartz is the more likely guy at this point, but I'm not expecting it.

@mikerothstein: At this time of year, a lot of what you see is based on last season, the draft and free agency. The Lions had a mediocre defense last season, didn't make any major additions during free agency and spent the draft focusing on the offensive line. That's probably why. That DeAndre Levy is still out is another reason. That said, I've been impressed with what I've seen from the defensive line so far. There's a lot of talent and depth there and the Ezekiel Ansah/Devin Taylor defensive end combination could be powerful. The linebackers are a thin group and a concern, particularly in pass coverage. The secondary is improving, and Rafael Bush has appeared to rebound well from last season's pec injury, but there are some things to prove there.

@mikerothstein: Absolutely. And that is why you should take anything you see and hear in preseason accordingly. Remember, the 0-16 Lions were 4-0 in the preseason, too. That said, the receiving corps has some good depth with three reliable options. That's a benefit. And Matthew Stafford -- again, it's just preseason -- appears to be comfortable with the offense. It's all going to come down to the offensive line, though. If the five up front can't give Stafford time or open holes for Ameer Abdullah, anything Jim Bob Cooter draws up won't matter. And right now, the offensive line is the biggest question on the team.

@mikerothstein: It is both normal and an accurate reflection of where he is right now. A'Shawn Robinson is going to make the roster and he has a bright future, but defensive tackles for the Lions are asked to do a lot from a speed and rush perspective. It takes time to learn. Robinson is going to get a ton of snaps in the preseason, and he's been making progress during camp. But it's going to take a little bit of time. The good thing for him is that between Haloti Ngata and Tyrunn Walker, the Lions are in good shape there. I would expect Robinson will start the season as the No. 4 tackle and will likely move to No. 3 by season's end.

@mikerothstein: He's getting better. Thought he played well in the preseason opener Friday night against Pittsburgh and sealed blocks well. He and Joe Dahl seemed to work well playing next to each other, which is a good sign for the long-term future of the Lions' offensive line. I don't expect him to challenge Travis Swanson early this season, but if Swanson struggles, he could get a shot. The next three weeks will be huge for his progress since he's not likely to see snaps once the regular season starts at this point unless there's an injury.

@mikerothstein: I wasn't there last night, but it was pretty surprising to me to see it. There's a bunch of reasons for it. The coaching staff might have wanted to get a longer look at Zach Zenner, who has far less experience than Stevan Ridley. Ridley might legitimately be behind Zenner on the depth chart as well, although the two have been splitting reps from what I've noted during camp. I think both end up making the roster, but if Zenner continues to get reps before Ridley, that definitively puts Ridley on the roster bubble.

@mikerothstein: Still not a battle. Dan Orlovsky is the No. 2 quarterback. Jake Rudock is the No. 3 quarterback. Rudock had a good debut and looked far more comfortable than I expected. Here’s the wet blanket of reason: Most of the guys Rudock faced will not be on 53-man rosters this fall, whereas Orlovsky faced a bunch of depth backups that have a shot at making the Steelers. It wouldn’t surprise me to see Rudock get some No. 2 reps in the preseason because it’ll give the Lions a good idea of where he is. But at this point I don’t expect Jim Caldwell to go into a season without an experienced backup (or at least an experienced in the system backup), so Orlovsky it is. That said, if Rudock keeps playing well, he should either be the No. 2 quarterback or push for the job in 2017. Right now he’s playing well enough to earn a roster spot.