The Jacksonville Jaguars have issues on the interior of their offensive line, namely at the center and right guard position. This is one of the many reasons people like to point out when they're arguing that rookie quarterback Blake Bortles should sit early on in the regular season, even if he's outperforming veteran Chad Henne.
The problem with this notion though, is that it's misguided. The Jaguars don't know who they will be starting at the two positions just yet. They've had guys like rookie Brandon Linder stand out, in a good way, at both center and right guard. Finding the person to put next to him has been the big issue and it's shown up in games.
In the running game.
Though it is preseason, which means the starters haven't played a ton, the Jaguars currently are in the top half of the NFL for pass protection grades according to Pro Football Focus. More specifically, they're ranked best overall cumulatively. If you pay attention during the games, it's clear to see the pass protection has been leaky a handful of times, but for the most part hasn't been an issue.
In fact, the Jaguars offensive line collectively have just given up just three sacks, three hits on the quarterback and five hurries in the two games combined*. Two of those three sacks have been given up by Michael Brewster and Jacques McClendon (at RG). One of those two will not be starting when the regular season begins.
On the flip side, the issue for the Jaguars on the offensive line is in the run blocking department. The Jaguars rank 28th overall on Pro Football Focus in run blocking through the first two games. The two biggest culprits again being Brewster and McClendon (at RG). Teams have been able to penetrate on the interior on running plays, and unlike a passing play where a quarterback with decent pocket presence can move or slide to avoid the pressure, a running play is generally dead in the backfield for a loss or no gain.
There have been 15 tackles for loss against the Jaguars combined in the first two games, for comparison's sake the Jaguars have just nine, and their defense has been very good so far. The Jaguars have averaged just 2.8 yards per carry in the preseason so far and neither the first team or beyond has looked very consistent with the running game. That has been the biggest issue so far in the preseason on the offensive line, not pass protection.
Fans are right to be worried about the center and right guard positions on the offensive line, but seemingly for the wrong reason.
*NFL.com stats list the Jaguars quarterbacks having being sacked just a single time while ESPN.com lists them being sacked two times, but sack numbers often differ depending on who the blame is laid on.