He missed just one league game in the 2013–14 season as he helped the club to secure a play-off spot, where they were beaten by Cambridge United at the semi-final stage. He was an ever-present throughout the 2014–15 league campaign, as Halifax posted a ninth-place finish, and signed a new contract in the summer. Halifax were relegated at the end of the 2015–16 season, and Glennon spent the second half of the season as back-up goalkeeper to loan signing Sam Johnson. He joined Buxton on loan in January 2016. He announced his retirement after he was released by Halifax. However, he played once for Scarborough Athletic after being coaxed out of retirement by manager Steve Kittrick. He again came out of retirement in February 2017, to play one game for AFC Emley in a Northern Counties East League Division One against Brigg Town after regular goalkeeper Graham McLachlan picked up a suspension.