also refused to play due to the appointment of Teddy Holland as team manager and the changing of the rules regarding the selection committee. Because of this, O'Sullivan and his teammates failed to fulfil their opening two fixtures in the 2008 National Hurling League. He was reinstated at full-back for Cork's subsequent championship campaign, but received harsh criticism for his performances. On 10 August 2008, O'Sullivan played his last championship game for Cork in an All-Ireland semi-final defeat by Kilkenny. His "cameo of redemption" was praised, with the Irish Times also describing O'Sullivan's performance as "his best display of the year". After the game O'Sullivan let emotions get the better of him and he was visibly distraught as he walked down the tunnel, gripping the crest on his jersey. O'Sullivan missed Cork's National League campaign in 2009 due to the players withdrawing their services for the third time in seven years. The third strike was particularly difficult for O'Sullivan as his father, Jerry, was the chairman of the Cork County Board. On 12 May 2009, O'Sullivan announced his intention not to return to the Cork senior team for the championship. He later revealed that his decision was influenced by a new rule which made the wearing of helmets compulsory. O'Sullivan also revealed that he hinted to team manager Denis Walsh about a change of position from full-back. He stated: "After the game against Kilkenny last year, I didn't feel I could play again in the full back line. I told him this and I asked him if I could play a role somewhere else on the field and he said he would think about it. Which he did and he was honest and said he didn't think there was...I took a few hours to think about it but I had made up my mind after the Kilkenny game that full back was no more for me so I just had to stick by it." Coaching career Cork Under-16 O'Sullivan began his inter-county coaching career in 2014 when he was appointed manager of the Cork under-16 development team. On 29 August 2015, he guided the team to an All-Ireland title after a 3-09 to 0-15 defeat of Kilkenny in the final at Semple Stadium. Senior On 16 October 2015, O'Sullivan became a selector with the Cork senior team under Kieran Kingston. His first season as part of the management team saw