Kerry senior side during the 1993/94 National Football League playing three games He made his Munster Senior Football Championship debut against Limerick later that season. He later played in the Munster semi-final loss to Cork. He played in all bar one of Kerrys National Football League games in the 1994/95 season. Later that summer wins over Limerick and Tipperary seen Hassett qualify for a first Munster Senior Football Championship. In the final, despite a point from Hassett, Kerry fell short to Cork on a 0–15 to 1-09 scoreline. He would only play in three of Kerrys 1995/96 League games. Wins again over Tipperary and Waterford seen Hassett and co back in the Munster final against Cork. A 0–14 to 0–11 win seen Kerry win a first Munster title since 1991 and a first senior title for Hassett. In the All-Ireland final Kerry faced Mayo. It was many of the Kerry sides, including Hassetts, first game in Croke Park and Mayo had too much for the young Kingdom side on a 2–13 to 1-10 scoreline. Hassett was appointed captain of the Kerry side for the 1996/97 season. He would go on to captain the side to the National League title after a win over Cork in the final. He missed out on the side Munster championship opener with Tipperary, but was back for the final against Clare. In the end Hassett won his second Munster title after a 1–13 to 0-11 point win as well as accepting the cup as captain. Injury lead to him missing out on the All-Ireland Semi-final and later final that Kerry won. This led to his younger brother Liam standing in as captain. There was controversy at the end of the year when he did not receive an All Ireland medal which led to him and brother Liam not playing with Kerry for the 1998 season. He made his return to the team in the team during the 1998/99 League His only championship game was when he came on as a sub in his sides Munster semi-final was over Clare. He played in all eight of Kerry's 1999/00 National League games a Kerry lot out to Meath in the semi-final. Come championship he appeared as a sub in Kerrys first three games, including the Munster final win over Clare. He was a sub once more in the drawn All-Ireland semi-final with Armagh, he was back in