Hay made his international debut for Great Britain in the 2009 season, starting with an appearance at the 2009 IAAF World Cross Country Championships in the junior race. He ran in the 1500 metres at the 2009 World Youth Championships in Athletics, being eliminated in the heats. At the end of the year he came 23rd in the junior race at the 2009 European Cross Country Championships. On the circuit he placed third in the junior 3000 m at the Aviva London Grand Prix and won the Gateshead leg of the UK Cross Challenge series. He returned to the cross country internationals the following year, improving to 62nd at the World Cross and 14th at the European Cross. That same year, he made his debut in road running at the Guernsey Easter Running Festival, winning the 10K run and coming runner-up in the half marathon.