 O'Sullivan missed some of Kerry's 2000/01 league campaign, playing in 5 of the 7 games, only starting two of them.He was back in the starting 15 for the first round of Munster where Kerry took on Tippereary, with him moving to right half back, where he would play for the season.Kerry started the defense of their Munster and All Ireland titles with a comfortable 3-17 to 1-04 hammering of Tipp.