That season saw Sheehan record his only quarter-final finish, beating Jack McLaughlin in his first-round match at the 1987 Irish Professional Championship before losing 3–6 to Dennis Taylor.

Having played in only one event - the 2007 Irish Professional Championship - in twelve years, Sheehan entered Q-School in 2012 in an attempt to re-qualify for the main tour.

He had earlier entered four PTC tournaments during the 2011/2012 season, losing to Joel Walker, Chris Norbury, Zak Surety and Anthony Cronin, and showed no better form at Q-School, where he was defeated 4–0 by Vinnie Calabrese, 4–1 by Saqib Nasir and 4–0 by Scott Donaldson.

The following season, he again played in the PTC events, but lost three of his four matches, to Allan Taylor, Joe Swail and Nico Elton respectively.

At the Lisbon Open in December 2014, Sheehan won two matches to reach the last 128, where he was drawn against fellow veteran Jimmy White.