In 2002, he became a UEFA assistant referee, one of only 3 from the UK at the time.[1]
He was appointed to the (Football League) National List of referees in 2004.[1] Also in 2004, on 6 March, he was named Combined Services Sports Official of the Year, due to his work for sport within the RAF. He had been posted to the Middle East at this time, so his parents travelled to London to receive the award from the Princess Royal on his behalf.[citation needed]
Drysdale attracted media attention in 2007 after Bradford City's Dean Windass received a five-match ban for swearing at him in the car park after a home game against Brentford on 2 January.[6]
In February 2021, Drysdale was involved in an altercation with Ipswich Town midfielder Alan Judge after Judge was shown a yellow card. Drysdale was subsequently charged with improper conduct by the Football Association and removed as the referee for his next game.[7][8]
