Newcastle United's attempts to sign Brazilian defender Douglas have been further complicated by an issue over citizenship.
Towering centre-back Douglas was granted Dutch citizenship last year after expressing an interest in playing for Holland at international level.
FIFA rules state that a player attempting to play for a new nation must live in that country for at least five years.
In order to meet that criterion, Douglas must stay in Holland until the end of August to have a chance of playing for the Netherlands.
Newcastle have been widely reported to have agreed a fee of £5m with FC Twente for the defender, who may be forced to delay the move if he still wishes to pursue his ambition of playing for his adopted homeland.
Douglas now seems likely to begin pre-season training with Twente rather than on Tyneside.