Scrum-half Danny Care says selecting players for international teams on the basis of their residency or relations will inevitably breed resentment.
Willi Heinz, who has an English grandmother but was born and raised in New Zealand, was picked ahead of Care in England's World Cup squad.
"Players are just pawns. You look at it and is there much loyalty in it? Maybe not," he told Rugby Union Weekly.
"Some are given an easier route than those who worked a fair bit harder."
Care, 32, has won 84 England caps, but only one of those has come at a World Cup. He was ruled out of the 2011 tournament with a toe injury and was third-choice scrum-half in 2015, making a solitary appearance in England's 60-3 dead-rubber win over Uruguay.
He says that he holds no hard feelings towards Heinz, who moved to Gloucester in 2015 from Canterbury-based Crusaders, but believes the current eligibility rules are unfair.
Second row Devin Toner was overlooked for Ireland's World Cup squad in favour of South Africa-born Jean Kleyn, who served out the required three-year residency period in August.
World Rugby vice president Agustin Pichot tweeted that he was sympathetic to Toner's predicament. The governing body has already changed the rule, extending the residency period to five years from the end of 2020.
"I started playing rugby at five in England, dreamed of playing for my country in a World Cup," continued Care.
"You do all the hard work, you stay in England, don't look to play for a club abroad to make more money because you want to play for England and win a World Cup - now that is not going to happen.
"A lot of players who have done well for whatever country and it comes to the World Cup, the pinnacle, where you hope that loyalty and hard work is paid back and it is taken away from you. That is the disappointment. That is why is hurts so much."