"I'm very disappointed, but I have to do what I have to do," Soriano told ESPN 1000's Bryan Dolgin on Friday. "I'm battling. Now I think I want to get an operation sooner than later ... to get ready for next year. I have to play with one leg now."
Soriano has played in just two games since Aug. 29.
"He's going to see his own doctor, I think to get a second opinion, and we'll probably know something the next few days," Cubs manager Lou Piniella said. "I would categorize it as doubtful that he'll return.
"I would think if he has a procedure before the end of the year, it would be to clean it out."
Soriano struggled this season, batting just .241 with 20 home runs and 55 RBIs in 117 games.
The Cubs started Friday 11.5 games behind the St. Louis Cardinals in the National League Central division.
"[The injury is] not of a serious nature," Piniella said. "So he should be ready to go for sure by spring training.
"But possibly, he might play some here the rest of the year. But I would say that's doubtful."