Italy and Papua New Guinea have been forced to make one change each to their World Cup squads.
Former Salford forward Vic Mauro is out of the Italy squad, and will be replaced by Tim McCann, of Tweed Head Seagulls.
Penrith Panthers hooker James Segeyaro has been forced to withdraw from the Papua New Guinea squad, with Joe Bruno, from domestic club Rabaul Gurias called up in his place.
The Papua New Guinea squad arrives in the UK on Tuesday, as do the respective squads from Australia, Fiji and Samoa.
The Cook Islands squad arrived early on Monday, and are in camp in Doncaster this week ahead of their warm-up match against New Zealand.