When head coach Andy Farrell announced the Ireland squad for their two remaining 2020 Six Nations Championship fixtures in October, delayed due to the COVID-19 pandemic, Wycherley was one of six players who, though not being called up to the squad, would train alongside it. Wycherley received his first international call up when named in the squad for Ireland's tests against Japan and the United States in July 2021, making his senior competitive debut as a replacement in the 71–10 win against the United States on 10 July 2021.