The Norway international was forced to leave his country's squad early after being injured just 16 minutes into Norway's 2-1 defeat by Wales last week.
Reports in Germany suggest the 28-year-old could miss Dortmund's clash with Werder at Signal Iduna Park. However, the injury is not expected to keep Ryerson out for an extended period.
Ryerson has become an important option for Dortmund on the right, and his absence would leave the club needing to adjust their defensive setup.
Maximilian Beier is one possible replacement and could be asked to operate as a right wing-back if Ryerson is not cleared to play.
