 In March 2015, Jaer akatumidzwa zita muSouth Africa Under-20 training group sechikamu chekugadzirira kwavo 2015 World Rugby Under 20 Championship. Kunyange zvazvo asina kupinda mumutambo wehushamwari neVarsity Cup Dream Team muna Kubvumbi 2015, akaverengerwa muchikwata chakatenderera Argentina muna Chivabvu 2015. Akatanga mutambo wavo wekutanga, achihwina muedzo mukukunda kwe25 22, asi haana kuratidzwa mumutambo wechipiri. Pakudzoka kwechikwata, akatumidzwa zita muchikwata chekupedzisira che2015 World Rugby Under 20 Championship. Akatamba kunze kwebhenji mumutambo wavo wekutanga mumutambo weB B wemakwikwi, kukunda 335 vachipesana nevanogamuchira Italy, asi haana kutumidzwa muchikwata chezuva remutambo nekuda kwekukunda kwavo 408 vachipesana neSamoa kana kukunda kwavo 4613 vachipesana neAustralia, izvo zvakaona South Africa ichipedzisa kumusoro kweBoka B kuti ikwanise kuenda kuma semi-fainari ine rekodhi yakanakisa yechikamu chemapoka mumakwikwi. Jaer akashandiswa semutsivi mumutambo wavo we semi-fainari vachipesana neEngland uye akarova muedzo wekutanga weSouth Africa mumutambo muminiti ye77, asi haana kukwanisa kuvadzivirira kurasikirwa 2028 kuti vabviswe mumakwikwi neEngland kwegore rechipiri rakateedzana. Akatanga mutambo wake wekutanga wemakwikwi mumutambo wavo wechitatu-mutambo wekutamba neFrance, achibatsira South Africa kukunda 31-18 kuhwina nzvimbo yechitatu mumakwikwi. 