The injury to his right foot will be further reviewed by a specialist to rule out the need for surgery, but it will require a six-week period of imobilisation.
That means that the 24-year-old Jones has been ruled out of contention for a place in Ireland's Rugby World Cup squad, which will announced on Monday at 1pm.
Ireland team manager Paul McNaughton said: "The squad and management are bitterly disappointed for Felix to suffer an injury at such a vital time in terms of selection for the final touring party.
"He had certainly put himself into contention over pre-season and the games in the last three weeks. We all wish him a speedy recovery and that he is back playing as soon as possible."