 Cardle was released by new Vale manager Lee Sinnott in May 2008, and subsequently returned to Scotland to join Airdrie United.He played for Airdrie in the final of the Scottish Challenge Cup at McDiarmid Park, helping his new club to beat Ross County on penalties to claim their first trophy.Cardle was red-carded in his final match for Airdrie, against Livingston on 7 March 2009, after an on-field incident with captain Marc Smyth.