[citation needed] In 2008 Kerwick made his National Hurling League debut against Offaly in 2008, lining out at right half-forward and scoring 1-1 from play.
Later that season he made his championship debut as Tipperary later reached the Munster final where they defeated a resurgent Clare team by 2–21 to 0–19.
[3] After a six-week lay-off and a facile semi-final win over Limerick, Tipp qualified for an All-Ireland final meeting with Kilkenny.
Two quick goals in the space of a minute, one from a penalty by Henry Shefflin, sealed a 2–22 to 0–23 victory and defeat for Tipperary.
[6] Kerwick sang "The Galtee Mountain Boy" following the presentation of the Liam MacCarthy Cup to Tipperary, reminiscent of the singing of The West's Awake after Galway's win in 1980.