Republic of Ireland captain Seamus Coleman said his side's shock 1-0 home loss to Luxembourg on Saturday was "embarrassing".
Gerson Rodrigues scored an 85th-minute winner for Luxembourg in Dublin, consigning the home side to one of the darkest days in their footballing history.
Luxembourg's win in was only their fourth away victory in Euro and World Cup qualifiers in 125 tries since 2008, and it dropped Ireland to back-to-back losses to begin a World Cup qualifying campaign for the first time since 1970.