The San Francisco 49ers defeated the Las Vegas Raiders 22-19 in a preseason game in Las Vegas, but the result was tempered by a growing list of injuries that further strain the club’s depth chart three weeks before the regular-season opener. Starting right guard Dominick Puni suffered a posterior cruciate-ligament sprain in his right knee and will miss "several weeks," head coach Kyle Shanahan said. Puni’s absence magnifies an offensive-line unit that was already considered a vulnerability as it works to protect quarterback Brock Purdy. Shanahan noted that no player sustained a season-ending injury, yet acknowledged the timing leaves Puni questionable for Week 1. Undrafted rookie running back Corey Kiner exited with a high-ankle sprain, and reserve back Patrick Taylor Jr. dislocated a shoulder. While receiver Brandon Aiyuk (knee), defensive end Nick Bosa (neck soreness) and several secondary pieces are progressing, the club is expected to place multiple injured players on the PUP or injured-reserve lists to start the year. Despite the attrition, several young defenders impressed. Cornerback Chase Lucas produced an interception and a late sack, and rookie linebacker Nick Martin led the team with five tackles, bolstering their bids for roster spots. San Francisco closes the preseason Saturday against the Los Angeles Chargers before finalising its 53-man roster on Aug. 26.