The San Francisco 49ers enter training camp with very few offensive starting jobs completely up for grabs.
Left guard is the exception.
Connor Colby, Robert Jones, Brett Toth and rookie Carver Willis will enter camp competing for the position between Trent Williams and Jake Brendel.
It might not have the star power of a wide receiver competition or the intrigue surrounding the 49ers’ new-look defense, but this battle could have a major impact on San Francisco’s offense.
Brock Purdy needs better protection. Christian McCaffrey needs consistent running lanes. Kyle Shanahan needs an offensive line he can trust when games tighten late in the season.
That makes the 49ers left guard battle one of the most important competitions to watch throughout training camp.
San Francisco already knows what they have at several offensive line positions.
Williams remains the anchor at left tackle. Brendel returns at center, while Dominick Puni and Colton McKivitz give the 49ers established options on the right side.
Left guard remains the question.
The position was already an area worth watching last season, and San Francisco enters 2026 without a clear favorite who has proven he can hold the job long term.
Shanahan’s offense depends heavily on timing, movement and getting blockers into space. A weakness along the interior can disrupt everything from outside-zone runs to Purdy’s ability to step into throws from a clean pocket.
If this battle is decided by NFL experience in San Francisco’s system, Connor Colby has an obvious argument.
The 49ers selected Colby in the seventh round of the 2025 NFL Draft after a decorated career at Iowa.
He appeared in 13 games as a rookie and made six starts. Colby logged 447 snaps at left guard and another four at right guard.
Colby finished with a 50.7 overall PFF grade, although his 62.5 run-blocking grade showed more promise in that area.
The experience matters.
Colby has already been thrown into NFL games, learned where his weaknesses are and had another offseason to develop.
He also has the size San Francisco wants inside at 6-foot-5 and 309 pounds.
The question is whether the 49ers saw enough progress during the offseason to trust him with the job permanently.
Colby entered the league with extensive college experience. He played in 51 games at Iowa and made 50 starts across right guard, left guard and right tackle.
That versatility was one of his biggest selling points coming out of college.
Now he needs to prove he can turn that experience into consistency.
Carver Willis could be the most intriguing player in the entire competition.
San Francisco selected Willis with the No. 127 overall pick in the fourth round of the 2026 NFL Draft.
He spent six college seasons between Kansas State and Washington, developing experience across the offensive line before entering the NFL.
At 6-foot-5 and 303 pounds, Willis possesses the athletic profile that makes him an interesting fit for Shanahan’s offense.
The biggest issue is experience at guard.
Willis primarily played tackle in college and is making the transition inside.
That could make winning a Week 1 starting job difficult.
However, the 49ers did not spend a fourth-round pick on Willis without seeing developmental potential.
If he adapts quickly to playing inside and handles NFL power during camp, his athleticism could separate him from the other candidates.
There is also a long-term element to consider.
Williams will not play forever.
San Francisco needs to continue developing young offensive linemen instead of relying exclusively on veteran stopgaps.
Willis could eventually become an important piece of that transition.
Whether that begins immediately at left guard will be decided over the next several weeks.
Robert Jones brings something neither Colby nor Willis can offer.
Experience.
Jones enters his sixth NFL season at 27 years old. He is listed at 6-foot-4 and 322 pounds, making him one of the heavier options competing for the position.
That size could become valuable against powerful interior defensive fronts.
Jones may not offer the developmental upside of Colby or Willis, but the 49ers may ultimately value stability more than potential.
Training camp competitions are not always won by the player with the highest ceiling.
Sometimes they are won by the player who makes the fewest mistakes.
Jones has enough NFL experience to understand protections, assignments and what is expected from an interior offensive lineman.
If the younger players struggle, he could quickly become the safest choice.
Brett Toth should not be completely dismissed.
The 29-year-old enters his seventh NFL season and brings extensive professional experience.
At 6-foot-6 and 304 pounds, Toth also provides San Francisco with positional flexibility across the offensive line.
However, he appears to enter camp behind the primary contenders.
That does not mean he cannot change the conversation.
Injuries happen quickly during training camp, especially along the offensive line. One strong preseason performance can also dramatically change how coaches view a position battle.
Toth’s best path may be proving he can provide reliable depth at several positions.
Still, if Colby, Willis or Jones struggle, the door remains open.
Right now, Colby deserves the slightest edge.
He already has starting experience in San Francisco’s offense and has had an entire offseason to address the weaknesses that showed up during his rookie season.
That does not make him the safest long-term projection.
Willis might ultimately have the highest ceiling.
The rookie’s athleticism and draft investment make him difficult to ignore. If he handles the transition from tackle to guard faster than expected, this competition could change quickly.
Jones represents the veteran fallback.
Toth remains the wild card.
There may not be a dramatic gap between any of them entering camp.
That is exactly what makes the competition so important.
This battle will affect Brock Purdy as much as anyone.
Interior pressure is one of the fastest ways to disrupt an NFL quarterback.
Edge pressure can sometimes be avoided by stepping forward in the pocket. Pressure directly up the middle eliminates that escape route.
Purdy’s success has often come from playing within rhythm and delivering accurately off Shanahan’s timing concepts.
A collapsing interior changes everything.
That is why finding a dependable left guard matters beyond simply filling the fifth spot on the offensive line.
San Francisco has invested heavily in its offense.
Purdy is expected to lead it.
McCaffrey remains the centerpiece of the running game.
Mike Evans, Ricky Pearsall and the rest of the receiving corps give the quarterback options downfield.
None of that works as efficiently if the offensive line cannot consistently protect the middle of the pocket.
Whoever wins the position will have one significant advantage.
He gets to play beside Trent Williams.
Few young offensive linemen could ask for a better situation.
Williams has spent years operating as one of football’s best offensive tackles and understands every detail of playing along the line.
For someone like Colby or Willis, lining up beside him could accelerate development.
It also reduces some of the pressure associated with winning the job.
San Francisco does not need its left guard to become the best offensive lineman on the roster.
The 49ers need him to complement Williams, execute assignments and avoid becoming the weak link opponents attack repeatedly.
There is another possibility San Francisco fans should prepare for.
The Week 1 starter may not necessarily keep the job all season.
Colby could begin the year because of his familiarity with the system while Willis continues developing.
Jones could win the opening job before one of the younger linemen eventually overtakes him.
Injuries could change everything.
That makes this more than a training camp storyline.
The 49ers left guard battle could continue well into the regular season.
San Francisco would obviously prefer someone to take control of the position immediately.
A prolonged competition would create questions about offensive line continuity and protection in front of Purdy.
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The 49ers have bigger names and flashier storylines heading into training camp.
That does not make left guard any less important.
Colby enters with the advantage of experience in San Francisco’s system.
Willis might have the highest upside.
Jones provides veteran stability.
Toth offers another experienced option if the competition remains unsettled.
My early prediction is Colby opens camp with the advantage, but Willis becomes the player most likely to push him before the season begins.
That would not be a bad outcome for San Francisco.
Competition should force both players to improve.
The concern begins if nobody separates from the group.
For a team expecting to compete deep into January, the 49ers cannot afford to have a glaring weakness sitting directly in front of Purdy.
The battle to make sure that does not happen starts at training camp.
The 49ers enter training camp without a clear starting left guard. Connor Colby, Carver Willis, Robert Jones and Brett Toth are expected to compete for the position.
Colby has an early advantage because he started six games as a rookie and already has experience in San Francisco’s system. Willis could become his biggest challenger during training camp.
Willis is a rookie offensive lineman selected by the 49ers with the No. 127 overall pick in the fourth round of the 2026 NFL Draft. He played college football at Kansas State and Washington.
Colby appeared in 13 games and made six starts during his rookie season. He played 447 snaps at left guard and finished with a 50.7 overall PFF grade and a 62.5 run-blocking grade.
The winner will line up between Trent Williams and Jake Brendel and will play an important role in protecting Brock Purdy while helping create running lanes for Christian McCaffrey.
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