Ben Bartch’s high-ankle sprain sidelines the 49ers’ left guard, forcing the team to lean on a rookie and reshuffle the interior line as Week 2’s run game showed promise behind the left guard. Colby stepped up in Bartch’s absence and impressed, hinting he could secure the starting job if Bartch goes IR, with Moss or Zakelj as immediate practice-squad options.

Spencer Burford’s knee injury adds another layer of uncertainty, while Jauan Jennings’ ankle, Kyle Juszczyk’s concussion protocol, and Siran Neal’s concussion evaluation keep SF’s skill positions and blocking schemes in flux. Robert Beal joining the practice squad stabilizes depth, and Colby’s early success could free up the offense to lean on the run more efficiently as the season progresses.

Overall, SF is navigating an injuried-heavy week with a rookie stepping up, potential IR moves looming, and a handful of players in concussion protocol, all while aiming to maintain offensive pace behind a revamped front five and a broader receiving corps.