HOENDERLOO, Netherlands, June 22 (Reuters) - Injured Dutch midfielder Ronald de Boer did minimal training on Thursday and may be in doubt for the Euro 2000 Quarter-final clash with Yugoslavia on Sunday.

De Boer twisted a hip in Tuesday's training and missed the 3-2 victory over France on Wednesday.

But goalkeeper Edwin Van der Sar, who was also absent against the French because of a thigh injury, trained on his own and later declared: 'I'm pretty sure I can play.'