FC Porto could be without their right-back Jose Bosingwa for their UEFA Champions League clash with Marseille on 24th October.
The 25-year-old Portuguese international pulled a thigh muscle in his right leg on Sunday during Porto's 1-0 win at Academica de Coimbra.
He was substituted in the 33rd minute of the game and is now expected to miss Portugal's forthcoming Euro 2008 qualifiers in Azerbaijan and in Kazakhstan.
And he is also a doubt for the Group A Champions League clash in Marseille on 24th October.
His injury comes as Porto enjoy a fine start to their domestic and European campaigns.
Sunday's win was the Portuguese title-holders' seventh successive victory at the start of their Liga campaign, while they have claimed four points from their opening two games in Europe, following a 1-1 draw with Liverpool with 1-0 win away to Besiktas.