Yennaris represented England at U17, U18 and U19 level. He made two appearances in the U17s' successful 2009 Nordic Tournament campaign. His solitary U18 cap came with a starting appearance in a 3–0 friendly win over Poland on 16 November 2010. Yennaris played in six friendlies for the U19s in late 2011 and early 2012, which were scheduled after the team received a bye to the elite round of the 2012 European U19 Championship qualifying. The friendly matches included three appearances at the 2011 Limoges Tournament, which England won. He was also eligible to represent China, Greece and Cyprus at international level.