After starting his career based in Japan, Barsoton emerged as a junior athlete in 2013 by placing second to Ronald Kwemoi at the national cross country trials. He was chosen for the junior team at the 2013 IAAF World Cross Country Championships and claimed the silver medal in both the individual and team races, having finished adrift of the comfortable favourite Hagos Gebrhiwet. After a runner-up finish behind Bedan Karoki at the Kenyan Cross Country Championships, he led Kenya to a sweep of the medals at the 2014 African Cross Country Championships, winning the race with his teammates Kipruto Kangogo, Rono Cherop and Solomon Kirwa Yego completing the top four. He also proved himself on the track that year with a 10,000 metres best of 27:20.74 minutes, ending the year fifth on the world rankings.