Hull could be without David Meyler and Abel Hernandez when they head to Portugal for pre-season training next month.
The Tigers are set to travel to the Algarve from July 5 to 14 but international duty means Meyler and Hernandez could join the rest of the squad at a later date.
Meyler is with the Republic of Ireland at Euro 2016 and if they manage to progress beyond the group stages Hull could give the midfielder an extended break.
Hernandez is on duty with Uruguay at the Copa America Centario but they have already been eliminated, although they have one group game remaining against Jamaica next week.
It is unlikely that Hernandez will miss the trip to Portugal unless he picks up any kind of knock against Jamaica, although he didn’t feature in Thursday’s defeat to Venezuela and it remains to be seen if he will be handed any time on the pitch when Uruguay take on the Reggae Boyz.