On 3 March 2012, he was an unused substitute when Kilkenny CBS suffered a 2-09 to 1-10 defeat by local rivals St. Kieran's College in the Leinster final.
[2] On 3 March 2013, Deegan lined out at left wing-back when Kilkenny CBS defeated St. Kieran's College by 2-09 to 1-07 to win the Leinster Championship.
[3] He was switched to centre-back for the All-Ireland final against Dungarvan Colleges on 6 April 2013, however, for the second successive year he ended the game on the losing side after a 1-12 to 1-07 defeat.
[4] Deegan won a second successive Leinster Championship medal on 9 March 2014 after lining out at left wing-back in a 2-13 to 0-13 defeat of St. Kieran's College.
[5] He was again selected at left wing-back when Kilkenny CBS renewed their rivalry with St. Kieran's College on 5 April 2014, however, for the third year in-a-row Deeegan ended on the losing side after suffering a 2-16 to 0-13 defeat.
On 30 October 2016, Deegan lined out at midfield when O'Loughlin Gaels faced Ballyhale Shamrocks in the Kilkenny Senior Championship final.