Staley -- who already missed six games due to a broken fibula -- fractured and dislocated the finger during the team's 27-24 overtime loss to the Seattle Seahawks Monday in Santa Clara, Calif. He played through the injury before it swelled on Tuesday and he was tended to by the 49ers' medical staff.
San Francisco coach Kyle Shanahan announced Wednesday that Staley had surgery on the finger and is expected to miss multiple games.
"Joe Staley had his surgery, and he will not play this week. He'll probably be out a couple weeks," Shanahan said.
The six-time Pro Bowl selection has appeared in three games this season after starting all 16 games in 2018. He started every game between the 2011 and 2015 seasons, before missing three contests in 2016. He missed one game in 2017. The No. 28 overall pick in the 2007 NFL Draft signed a two-year, $28 million contract extension in June.
Justin Skule is likely to take over for Staley at left tackle for the 49ers. Skule also played left tackle during Staley's previous six-game absence. Skule, 22, was a sixth round pick out of Vanderbilt in the 2019 NFL Draft.
"I thought [Skule] did a very good job," Shanahan said. "He came in there and stepped it up right away. Did a good job in his first game and I thought he got better each week. We were happy with how he played and I'm glad we had a couple good backups through that."
The 49ers host the Arizona Cardinals at 4:05 p.m. EST Sunday in Santa Clara.