McGuckin began his club hurling career with St. Rynagh's and enjoyed much success. He was just out of the minor ranks in 1987 when he joined the club's senior hurling team. A defeat of Seir Kieran in that year's county final gave McGuckin his first championship medal. St. Rynagh's surrendered their title the following year but returned to the championship decider again in 1990. A 2-6 to 1-17 defeat of Birr on that occasion gave McGuckin a second championship medal. Once again St. Rynagh's failed to retain their title, however, the club reached the county final again in 1992. Lusmagh were accounted for on that occasion, with McGuckin adding a third championship medal to his collection. 1993 was another successful year for St. Rynagh's. A 1-16 to 1-14 defeat of Birr gave McGuckin his fourth and final championship medal. St. Rynagh's subsequently qualified for the provincial decider against Dicksboro. A close game developed, however, at the full-time whistle St. Rynagh's were the winners by 1-14 to 2-10, giving McGuckin a Leinster medal. McGuckin later played with the Naomh Éanna club in Wexford.
Inter-county
McGuckin made his senior debut for Offaly in a National League game against Antrim in 1990 and immediately became a regular member of the starting fifteen. It was a successful campaign as Offaly reached the final. A 2-6 to 0-10 defeat of Wexford gave McGuckin a National League medal. In 1994 McGuckin won his first Leinster medal following a 1-18 to 0-14 defeat of Wexford. Offaly subsequently reached the All-Ireland decider against Limerick. With five minutes left in the game Limerick were five points ahead and were coasting to victory. It was then that one of the most explosive All-Ireland final finishes of all-time took place. Offaly were awarded a close-in free which Johnny Dooley stepped up to take. Dooley was told by the management team to take a point; however, he lashed the ball into the Limerick net to reduce the deficit. Following the puck-out Offaly worked the ball up the field and Pat O'Connor struck for a second goal. The Offaly forwards scored another five unanswered points in the time remaining to secure a 3-16 to 2-13 victory. This sensational victory gave McGuckin an All-Ireland medal. Offaly retained the Leinster title following a 2-16 to 2-5 trouncing of Kilkenny in 1995. It was McGuckin's second provincial medal. Down fell to Offaly in the subsequent All-Ireland semi-final, allowing Offaly to advance to the championship decider and attempt to put back-to-back All-Ireland titles together for the first time ever. It was the first-ever meeting of Offaly and Clare in the history of the championship. The game developed into a close affair with Offaly taking a half-time lead. Four minutes from the end substitute Éamonn Taaffe first timed a long range free straight into the net to give Clare a one-point lead. After a quick equaliser Anthony Daly sent over a 65-metre free to give his team the lead again. Jamesie O'Connor pointed soon afterwards and at the full-time whistle Clare were the 1-13 to 2-8 winners.
