Editor’s note: This is the final installment of Matt Maiocco's position-by-position breakdowns leading up to 49ers training camp, which opens with their first full-squad practice on Saturday.
Who they have: Joe Staley, Alex Boone, Daniel Kilgore, Marcus Martin, Erik Pears, Brandon Thomas, Trent Brown, Joe Looney, Dillon Farrell, Ian Silberman, Andrew Tiller, Justin Renfrow, Ben Gottschalk, Sean Hooey, Patrick Miller
Who they lost: Mike Iupati, Anthony Davis, Jonathan Martin, Fouimalo Fonoti
Looking back: A unit that had been, perhaps, the strength of the offense was not nearly as imposing last season. Boone and Iupati struggled early in the season. Jonathan Martin had difficulty handling his chores at right tackle when he was forced into nine starts in place of oft-injured Davis. Kilgore might have been the 49ers’ best offensive lineman through the first half of the season when the center went down with a fractured left lower leg. Rookie Marcus Martin stepped in and was up and down in his eight starts. The offensive line never came together. Quarterback Colin Kaepernick was sacked 52 times and the run game was inconsistent, as featured back Frank Gore failed to average more than 3.5 yards per attempt in eight games.
Overall outlook: Staley, a four-time Pro Bowl performer, is the only offensive lineman assured at returning to the same starting spot as a year ago. There figures to be a lot of shuffling to compensate for the expected free-agent loss of Iupati and Davis’ unexpected retirement. The first thing on which the coaching must decide is the optimum position for Boone. He has been the starter at right guard for the past three seasons. But Boone might be the best option to replace Davis at right tackle. Once the 49ers decide where to place Boone, the rest of the competitions will become straight-forward. Pears, 33, a free-agent pickup from Buffalo, has a lot of experience at right tackle, but he moved to right guard last season. Brown, a seventh-round draft pick, saw a lot of action at right tackle in the offseason and showed promise. Kilgore will compete against Martin, who will also see time at the guard spots. Thomas figures to be in the mix for a starting spot, too. The 49ers might have some young talent on the offensive line, but with the shift to more of a zone-blocking scheme with a bunch of new faces, the lack of continuity could contribute to some issues with this position group.
Camp competition: Thomas could be the most-intriguing offensive lineman in camp. The 49ers selected him in the third round of the 2014 draft with the full understanding that he would be unable to contribute as a rookie after sustaining a torn ACL in a pre-draft workout with the New Orleans Saints. The 49ers had Thomas rated as a second-round talent. If their evaluation was correct, that should place Thomas in the mix to be a starter at left guard. Clearly, the 49ers selected Thomas with the idea that Iupati would not be re-signed. If Kilgore is healthy (he is currently on the active/physically-unable-to-perform list), he should win the job at center over Marcus Martin. Other than left tackle and whichever spot Boone is assigned, there should be competition throughout the offensive line.
Bottom line: Even with all the turnover that occurred throughout the 49ers' roster in the offseason, the position group that contains the most unknowns and question marks is right here. New O-line coach Chris Foerster has a significant challenge to find the right spots for each of his players and, then, getting that unit to mesh quickly into a competent group.