Coughlan was still just 18-years-old when he was added to the Glen Rovers senior hurling team in advance of the 1964 Championship. On 11 October 1964, he was a member of the extended panel when Glen Rovers claimed the championship after a 3-12 to 2-07 defeat of St. Finbarr's in the final. By the time the Munster Club Championship was completed nearly 18 months later, Coughlan had broken onto the starting fifteen. He claimed a Munster Club Championship medal on 10 April 1966 after lining out at midfield in the Glen's 3-07 to 1-07 defeat of Mount Sion in the final.