In December 2008 it was announced that Marriner, at the age of 37 and along with 26-year-old Stuart Attwell, would be invited to join FIFA's list of international referees for 2009. Marriner was called up to officiate at the elite qualification for the 2009 Euro Under-19s Championship, taking charge of Norway's 1–1 draw with Romania in Saint-Lô, and Romania's 3–0 defeat to France, also in Saint-Lô.