Manchester City have sent defender Sun Jihai to Germany in an attempt to cure his long-standing hamstring problem.
Sun has not played for City this season
The 29-year-old China international suffered the injury in pre-season and has consequently failed to appear for City this season.
"Every time Sun tried to come back, something happened which set him back a bit more," said Pearce.
"At the moment he is having a course of injections in Germany which we are hoping will solve the problem."
Sun is being treated by a specialist in Munich, who has previously cared for various City players, including Claudio Reyna.
The Blues boss added: "There have been so many false dawns we don't want to put a timescale on his recovery, we just hope it works."