The surgery will take place Thursday in Vail, Colorado, according to A's manager Bob Melvin.
Davis, who missed 33 games earlier this year with a strained left quadriceps, was placed on the disabled list Tuesday with a strained left hip. He underwent an MRI Wednesday that revealed the tear.
Davis said he believes the hip problem might be the result of overcompensating for the quad injury.
"We took a while to get him back [from the quad injury]," Melvin said Friday. "I thought once we got him back, he was over that hurdle. I guess it got progressively worse, and he wasn't saying a whole lot about it.
"Recently, the last couple weeks, it got to where he wasn't comfortable either swinging or running. It came to a head then, but it just wasn't getting any better, and the MRI revealed he needed to have surgery."
Davis batted .229 with three home runs and 20 RBIs in 74 games this season.
The A's are last in the American League West at 53-70.
Information from The Associated Press was used in this report.