The injury probably occurred during one of Stallworth's three punt returns. He saw limited time on offense and did not catch a pass.
"The good news is it is not a season-ending injury," Ravens coach John Harbaugh said. "We'll get it operated on right away and put a screw in it. Hopefully, we'll get him back by the bye week [Oct. 31]."
Baltimore signed Stallworth as a free agent in February. He was suspended last season after pleading guilty to DUI manslaughter, a second-degree felony, in the death of a dock worker in Florida.
Stallworth was driving when he hit 59-year-old Mario Reyes in March 2009.
His last action before this season was in December 2008 with Cleveland.
Information from The Associated Press contributed to this report.