Andrij Wosnjak made his international debut at the 2007 Biathlon Junior World Championships in Martell . There he was eleventh in the individual, 51st in the sprint, 56th in the pursuit and fifth in the relay. The following year he came in Ruhpolding to ranks 76 in the individual, 21 in the sprint, 13 in the pursuit and 10 in the relay. At the European Junior Championships of the Year in Nové Město na Moravě , he won his first international medal with a relay bronze medal alongside Vitaly Koschuschko, Artem Pryma and Vitaly Kiltschyzkyj . In 2009 he narrowly missed another medal win twice. First at the Junior World Championships in Canmore , where Wosnjak was 52nd in the individual, 22nd in the sprint, 35th in the pursuit and fourth in the relay, later in the year also at the Summer Biathlon World Championships in Oberhof in 2009 , when he was in the cross-country run - Competitions Fifth in the sprint and fourth in the pursuit, on roller skis 20th in the sprint and eighth in the pursuit. Even the 2010 Biathlon Junior World Championships in Torsby did not bring any further medals, with 13th place in the individual and sprint, 18 in the pursuit and eight in the relay, the Ukrainian was nevertheless able to place well. The international breakthrough finally came at the 2010 European Junior Championships in Otepää . Wosnjak initially just missed a medal in fourth place in the sprint, but then ran up to first place in the pursuit race and won his first title. In the individual, he narrowly missed a second gold medal against Andrei Turgenev. With the mixed season he was seventh. The 2010 Summer Biathlon World Championships in Duszniki-Zdrój were the last title fights for the juniors. Vosnjak was seventh in the sprint, eighth in the pursuit and won the silver medal with the relay behind the overpowering Russian representation.