England boss Shaun Wane has added four players to his squad for the training camp at Leeds Beckett University.
Huddersfield prop Matty English and centre Jake Wardle have been included, alongside Leeds front rower Mikolaj Oledzki and hooker Kruise Leeming.
It will be Wane's first physical session with the England players since he was appointed in February 2020.
His maiden match as England boss will be against the Combined Nations All Stars on 25 June.
Seven of Wane's original 35-man squad are based in Australia in the NRL but have regular contact with the coaches. Their unavailability, and injuries to others, led to the four extra names coming on board for Tuesday's camp.
England begin their World Cup campaign against Samoa in Newcastle on 23 October.
"Names will come and go as the season unfolds, but the players I've named reflect my current thinking," Wane said last week.
England training squad
John Bateman, Tom Burgess, Daryl Clark, Mike Cooper, Ben Currie, Matty English, Niall Evalds, Herbie Farnworth, Liam Farrell, Luke Gale, Oliver Gildart, Josh Griffin, Ash Handley, Zak Hardaker, Josh Hodgson, Tom Johnstone, Toby King, Morgan Knowles, Kruise Leeming, Jonny Lomax, Jermaine McGillvary, Paul McShane, Tommy Makinson, Dom Manfredi, Harry Newman, Mikolaj Oledzki, Mark Percival, Joe Philbin, Stefan Ratchford, James Roby, Dan Sarginson, Ryan Sutton, Luke Thompson, Sam Tomkins, Alex Walmsley, Jake Wardle, Kallum Watkins, Elliott Whitehead, George Williams.