St Helens pair Calvin Wellington and Elliot Jenkins and Coventry Bears' back Zak Williams are the other players yet to represent Wales.
Ben Evans, Ben Flower, Larne Patrick and Rhys Evans, who all made their last appearances at Rugby League World Cup 2013, have been selected alongside 20 of Wales' 22-man squad for last year's World Cup qualification campaign.
In total, the squad features 12 players from Super League clubs, nine players from Championship clubs, 13 players from League 1 clubs and four players from NRL and Australian clubs, including Ollie Olds of West Brisbane Panthers.
Kear said it was a stirring time for the team.
"Everybody is pretty excited about the World Cup," he said.
"The train-on squad is a mixture of those who have achieved with us and newcomers who have come to our attention. We want to be able to pick the best squad for the World Cup."
Aekins is part of a strong link between Northland and the Penrith Panthers.
Waimamaku's Corey Harawira-Naera is enjoying a strong debut season in the NRL where he has paired up with Rawene's James Fisher-Harris.
Fisher-Harris has endured a frustrating 2017 campaign as he has struggled with injuries, limiting him to just seven appearances so far this year.