Dundee born, Simon had played with a host of boys clubs including Celtic Boys, Dee Club and United Social before playing youth football and eventually securing his first professional contract with Montrose. He played just one senior game during his time at Links Park before moving to the junior scene on a season long loan with Downfield FC. In 2013, he signed for another junior side, Tayport FC, before moving to Australia for a spell. His goalscoring form at Tayport had caught the eye of Arbroath and in the summer of 2014, he joined the Gayfield Park side.
Six months into the season Simon had scored 18 goals for the SPFL League 2 side, by which time United had secured his signature at Tannadice on a two and half year deal for a reported fee of £50,000. He was loaned back to Arbroath for the remainder of the 2014-15 season following his signing and he finished up as the Red Lichties’ top scorer.
Simon joined up with his new United teammates for the 2015-16 pre-season and made his debut as a substitute during the Club’s opening game against Aberdeen. It took him just a few more days to open his goalscoring account, notching against Motherwell in a 2-0 win. First team opportunities were limited in his first season, with most games spent coming off the bench but he rounded off his first campaign by hitting a rich vein of form during the post-split fixtures, netting five goals in five games.