Real Madrid coach Julen Lopetegui confirmed Gareth Bale's injury in the LaLiga giants' shock 1-0 loss to Deportivo Alaves yesterday.
Bale's injury was not considered too major, however the 29-year-old missed Wales' training today citing his discomfort with the injury.
It is understood the 29-year-old forward has suffered a recurrence of a groin injury which saw him miss Real's Champions League loss to CSKA Moscow last week.
Wales' medical team will continue to assess Bale in the next 48 hours ahead of the 19.45 kick-off on Thursday.
Bale will be presented with an award on the pitch prior to kick off in Cardiff.
He is now the country's top scorer, having passed Ian Rush's 28-goal mark earlier this year.