Mailbag: Have the 49ers soured on Trey Lance? Biggest concern on both sides of the ball? What’s up with Kalia Davis and Jaylon Moore? Linebacker depth and more

The San Francisco 49ers are in Las Vegas for a two-day joint practice with the Las Vegas Raiders. On Sunday, the 49ers and Raiders will play a preseason game. Kyle Shanahan has already said that QB Brock Purdy will not play in this game. I would expect Trey Lance to get the start, but we'll see what Shanahan decides.

Let's jump into the latest 49ers mailbag. We didn't have many questions this week, so this should be a quick read.

Everyone knew when Lance was drafted he'd need game experience and practice reps to improve. The lack of game experience seems to just be dumb injury luck, but I'm having trouble understanding why to bring in Darnold & giving him equal reps unless they've soured on Lance. Thoughts? - Yossarian

It seems strange to me, as well. The only thing I can think of is that Shanahan no longer believes Lance is his guy. If that's the case, is it because of the injuries? They seemed to sour on Jimmy Garoppolo, in part because of injuries. Have they soured on Lance for the same reason?

Is it because of Lance's inconsistency? Everyone knew he would be a project, because of his lack of experience. He needs development, he needs reps, and he needs experience. We thought the 49ers would be patient and give him that.

My best guess is that the 49ers drafted Lance with the intention of being patient, letting him develop behind Garoppolo for year one, and then taking their lumps in year two as Lance developed. But Lance's season-ending ankle injury in week two sidelined the plan, along with the young QB.

Enter Purdy. And you know the rest. Now San Francisco has a team with Super Bowl aspirations and needs to put their best foot (or arm) forward. Purdy is QB1 for now, and Lance may not get another chance to be the starter.

What is your biggest concern on both sides of the ball going into the season? - ShoqMax

Offense: My biggest concern on offense is tackle. I'm a little concerned about Colton McKivitz being the starter, but I'm more concerned about the lack of depth at the position. Is McKivitz the answer? What if he or (gulp!) Trent Williams goes down and misses any extended time? Is Jaylon Moore ready (more on him below)? Who else can the team count on to keep Purdy, the QB who a few months ago had only one arm, upright and healthy?

I'm a little concerned about the quarterback position, but I think Shanahan will figure it out and have those guys ready.

Defense: My biggest concern on the defense is the edge rusher. Nick Bosa's holdout makes this even more concerning, but I'm assuming he will be back and in shape. I just hope he doesn't end up with a soft tissue injury like we often see from players holding out. I'm not worried about Bosa being ready to perform. I am a little concerned about the potential for injury, though.

The edge position opposite of Bosa is the bigger concern. Drake Jackson looked great at the beginning of camp but has not been as good over the past week. The 49ers really need someone at that position to make an impact. If not Jackson, who will step up? Will it be Clelin Ferrell? Austin Bryant? Will it be anyone?

What's up with Kalia Davis? Didn't hear his name in camp other than a DNP or 2. - DownByLaw

Kalia Davis has not been practicing. That's why you haven't heard much about him. The 49ers have held him out of practice for the past week, at least. Matt Maiocco, of NBC Sports Bay Area, reported it's due to a hamstring issue. Hopefully, that heals up quickly, because the 49ers are high on Davis, and I think he has a chance to make an impact on this team.

Even before the team started holding him out, I wasn't hearing much about him, though. Maybe it's because he was injured, or maybe he's still not ready. Davis, of course, missed his rookie year due to a knee injury he suffered late in the season before. And if you look at the unofficial depth chart the 49ers just released, Davis is way down the list. But I wouldn't read too much into that. I've heard the coaches aren't even the ones who release these early depth charts. I think it's done because the team is required to provide one at this point.

Who has been lining up at the backup Mike position primarily? - Zach M.

I haven't attended training camp, and I've had to rely on those who are there. So in order to answer Zach's question, I reached out to the great John Chapman to ask what he was seeing with the backup linebacker depth. He responded, "Looks like Demetrius Flannigan-Fowles has gotten most of the backup snaps at Mike. Marcelino McCrary-Ball would be next up behind him."

A couple of weeks ago, I predicted that McCrary-Ball would win the LB3 spot vacated by Azeez Al-Shaair. I just didn't think that Flannigan-Fowles or Oren Burks would be up to the task. But so far Burks has been getting those snaps, and Flannigan-Fowles appears to still be ahead of McCrary-Ball.

So maybe I'll be wrong once again. But I'm still high on McCrary-Ball.

Has Jaylon Moore finally turned the corner? - Nick E.

It sounds like Moore was on the rise, and was the leader in the clubhouse for the swing tackle spot. But he's been out with an injury (bone bruise) and hasn't been practicing. Nick Wagoner, of ESPN, reported yesterday that "Moore appears to be progressing well, as he did some work on the side."

So that's good news. We'll see how this injury affects the depth chart at tackle if it does at all.

That's all we have for this week. We'll be back with another mailbag next week. In the meantime, watch for the release of "The Hall of Fame Case for Roger Craig" podcast series. It should drop any day now. You can subscribe to the 49ers Camelot Show to be notified is its arrival.