Ghana striker Isaac Boakye is facing a race to be fit for the World Cup after suffering a knee injury in Wednesday's friendly clash against Stuttgart.

The 24-year-old Arminia Bielefeld star looks set to be sidelined for at least three weeks.

Boakye has scored eight goals in 25 Bundesliga games this season but has been struggling with a niggling knee problem for several months.

He will undergo surgery but is definitely out of Arminia's final three Bundesliga games of the season against Schalke, Duisburg and Cologne.