The 49ers are Shaking Up their Offensive Line in Two Key Places

This is a positive development.

Jun 10, 2025; Santa Clara, CA, USA; San Francisco 49ers offensive linemen Trent Williams (71), Nick Zakelj (63) and Ben Bartch (78) participate in a drill during an OTA at Levi's Stadium. Mandatory Credit: D. Ross Cameron-Imagn Images | D. Ross Cameron-Imagn Images

The San Francisco 49ers' depth has been exposed through a lot of the offseason programs. The depth along the offensive line got worse as the game went against the Denver Broncos, but the team has found two potential changes that could improve the group. 

Andre Dillard returns to 49ers at perfect time

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First, the 49ers got Andre Dillard back from the Physically Unable to Perform list. Dillard was expected to be the team's swing tackle, but he had been dealing with an ankle issue, which led to the 49ers playing Spencer Burford and Austen Pleasants at their two tackle spots. 

Dillard has not proven anything yet, but those two did prove that the bar is low for Dillard stepping up and seizing the backup job. The odds are that he could be the backup on both sides, making him an ideal swing tackle. This can also push Spencer Burford inside, where he has been better. 

Is Connor Colby ready to replace Nick Zakelj?

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Speaking of the inside, with Burford at backup left tackle, and Ben Bartch injured to start training camp, the team had to start Nick Zakelj at left guard through the early portions of the summer. Bartch returned and started in the preseason opener, showing that there is not much competition at the spot. 

Zakelj did start as well, but at right guard. The issue is that he struggled there and had been struggling all of camp, which is why he could not make it a competition while Bartch was out. 

So, when Bartch missed some time at training camp, it was seventh-round rookie Connor Colby starting with the first team, not Zakelj. 

May 9, 2025; Santa Clara, CA, USA; San Francisco 49ers offensive linemen Isaac Alarcon (67) and Connor Colby (75) work out during the teamís rookie minicamp. Mandatory Credit: D. Ross Cameron-Imagn Images | D. Ross Cameron-Imagn Images

Bartch is likely to start in preseason Week 2, but if he does not due to his injury, it would be interesting to see if the team starts the rookie this time around. 

To be fair to Zakelj, he took snaps at center and right guard. If he can offer three position versatility, they may be willing to keep him and Colby at the expense of backup center Matt Hennessy.

However, if Burford starts getting work at right guard, and Zakelj is behind Colby for backup work at left guard, Burford for backup right guard, and behind Hennessy as the backup center, he is not going to be on the roster in a few weeks. 

How quickly Dillard settles into the backup left tackle job and how much work Colby gets at backup left guard should be two notable developments to watch in the next week as the 49ers are starting to finalize their roster.