49ers vs. Cowboys Preseason Watch Guide: RB, OL, DL, LB, S/T

The 49ers on Thursday night at Levi's Stadium strap up against the Cowboys for their first preseason game of 2018. An easing back into the game can very much be expected from Kyle Shanahan and his staff, as far as the vanilla nature of the plays to be called and the limited reps for the starters. But that doesn't mean there aren't a ton of developments that can occur from within this game against Dallas.

Train your eye for Thursday night's preseason opener with this positional guide below. And refer to Eric Crocker's analysis of quarterback, wide receiver, tight end, cornerback and safety.

Running Back

One of the top signings of the 2018 offseason for any team was San Francisco’s deal with prize free-agent tailback Jerick McKinnon. Knowing he likely won’t be out there long against the Cowboys, I’m looking mostly for play speed. This will speak to his conditioning, the breakaway ability they coveted when letting Carlos Hyde walk in free agency, as well as McKinnon’s timing and comfort within the offense.

After that, the main event begins, and that’ll be a triple-threat match between Matt Breida, Joe Williams, and Raheem Mostert.

Breida is safe on the roster. He earned the No. 2 job last year—at times looking better than Hyde—and he’s taken his game up a notch in 2018. But he won’t go unchallenged, as he’ll be fending off a revived Williams, who was originally intended to have a role in this offense as Kyle Shanahan’s draft crush. Behind Williams is Mostert, who brings return speed to the backfield, and is also a core member on Richard Hightower’s special teams unit. All told, Williams will have his work cut out for him, as he’s got competition from both sides, not to mention a wild card in Jeremy McNichols.

Yards per carry, forced missed tackles and ball security will be a meaningful trifecta for all these runners. They’ll also be graded on pass protection. What they do with their opportunities in the preseason games will decide the bottom of the RB depth chart, and perhaps snap allocation during the regular season.

Keep in mind, the Cowboys have some solid linebackers, too, which makes this a good test to determine who is really worth that third RB spot. There is potential for them to see at least one, if not the entire corps of Sean Lee, Jaylon Smith and No. 19 overall pick Leighton Vander Esch.

Offensive Line

When it comes to six-time Pro Bowl left tackle Joe Staley and the preseason, there’s nothing to see here. However, the other four spots on the line, including on down the depth chart, will be an interesting watch Thursday night. This team changed out three of five starters, from the center to right tackle. There’s a lot of new pieces and unanswered questions, which they can only get a better grip on when the live action commences.

I’m curious how left guard Laken Tomlinson, in his second year in this system, holds up when it comes to protecting the depth of the pocket. I’m very interested to see how well priority signing Weston Richburg moves in space, and if he can maintain a strong base in pass-pro as smaller-stature center. No. 9 overall pick Mike McGlinchey also has me curious around his ability to get downfield in the run game and create long gains. He also hasn’t started a game at right tackle since 2015, his junior season at Notre Dame. So his natural mechanics and foot speed should be something to watch.

McGlInchey may also get some quality reps against DeMarcus Lawrence, who finished third in sacks in 2017 with 14.5.

And of course, most of us will have our eyes glued to the right guard spot looking for a clear front runner, if one emerges. Joshua Garnett is “listed” as the starter on the team’s first depth chart of 2018, but he hasn’t practiced due to a setback with his knee. Jonathan Cooper is a favorite to sneak up and grab the job, but Mike Person and Erik Magnuson have been getting the bulk of the work so far. The starting right guard job is the one that’s going to be most influenced by preseason performance, so watch close.

And overall, cohesion with the first team will matter. To see that this unit is in sync, not as permeable as a year before, and moving fluidly will be important.

Defensive Line

The player most under the microscope is without a doubt Solomon Thomas. It’ll be good to see how he performs against the Cowboys offensive line, which is one of the best in the league, featuring the highest earner ever in guard Zack Martin. It’s a great opportunity to assess Thomas in particular, to see how far he’s truly progressed this offseason. He’s looked mighty good in training camp, but live action against other teams is a different story.

DeForest Buckner, if he plays, will be one to watch. But with him, it’ll be most interesting to see exactly where he lines up. The 3-tech defensive tackle has been reportedly getting some time out at defensive end, where Robert Saleh feels they can get him in advantageous 1-on-1 situations. See if Buckner lines up wide and what the result is.

[DESIMONE: Interpreting Kiffin's pass-rush plan to build trap around 49ers' Buckner]

After those two, the third-most intriguing name has to be DE Jullian Taylor, the rookie seventh-round pick out of Temple. In Arik Armstead’s injury absence, he’s received time with the first team, and has impressed the staff, as well as his peers. Game time snaps will be the real indicator if he’s ready or not. If Taylor plays well, he could legitimately earn the starting job over the veteran Armstead before Week 1 against Minnesota.

Beyond that, Ronald Blair and Cassius Marsh are two big ones on the D-line, as both have upside as edge rushers in a group that is pretty thin. Lengthy new addition Jeremiah Attaochu, the former Chargers rush linebacker, is also in that same grouping, but hasn’t been as loud at camp as some expected. All of these guys will be battling for a featured role when Saleh calls a play to defend the pass.


Reuben Foster, while the most polarizing of the group, is the least interesting study when it comes to preseason ball. But eyes should be on the battle to be his regular running mate from Week 3 on. Now, Malcolm Smith says he’s eager to play in the preseason opener vs. the Cowboys, which is atypical of a veteran, but this should come as no surprise as Smith hasn’t seen action in over a year. Not only does he want the job, but he wants to keep his NFL career alive.

But rookie Fred Warner, the team's first defensive pick in 2018, is a talent that cannot be ignored.

Coach Saleh has been careful as to not hype him up too much, but the unfiltered quotes by his teammates, as well as reporter Joe Fann, who is there every day, leads me to believe Warner has transitioned well from his hybrid role at BYU to the speed and physicality of the NFL. There’s been real talk about his coverage ability, as well as his intense style of play in the box. It’s possible the audience gets a glimpse and sees how far behind Smith and Brock Coyle he really is, if at all.

Special Teams

When it comes to special teams, it’s important to revisit the two running backs, Williams and Mostert. Whoever makes the roster has to have the most total value in both the backfield and when it comes to special teams. Since they ran with Mostert last year, he has the upperhand until Williams proves otherwise, so he has to have himself a game, including on the special teams gunner squad if he gets a chance.

Aaron Burbridge is another name who carries special teams value. But if there are other players making tackles before him, and he's not disciplined in his own assignments, he may be someone that is deemed cuttable, especially with the wide receiver depth this team has so quickly accumulated. There's pressure on him to perform. But keep an eye out on who is impacting the field position game, for better or worse.

Media courtesy AP Images, USA Today Sports Images

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