News of the 21-year-old's omission follows reports that police recently investigated a child protection-related complaint against him.
Wallace has denied any wrongdoing and is planning to appeal against his deselection from the tournament.
"We intend looking at options to appeal this decision," BBC Sport quotes the athlete's solicitor as saying.
Although Wallace was not arrested or questioned as part of the police investigation, the complaint is said to be the reason behind his deselection.
"We have put the committee on notice that if this decision is not reversed, we will have no option but to seek an injunction," his legal representative added.
"Our client has not been arrested or questioned by the police. We are convinced that Mr Wallace will be exonerated in due course."
Ireland are expected to call up another athlete to replace Wallace.