Viljanen competed on the Scandinavian Darts Corporation (SDC) Tour in 2014, and finished third in the Scandinavian Order of Merit. He was awarded a place in the 2015 PDC World Championship after Jarkko Komula, who had finished second on the Scandinavian Tour, was excluded following a suspension by the Finnish Darts Organisation. He lost 4–1 in the preliminary round to Sascha Stein.