Early career Gleeson began his career playing for
Western Suburbs FC of the
Central Premier League. After an extremely impressive showing at the
2007 Under-17 World Cup in
South Korea, Gleeson was offered week-long trials with English
Premier League clubs
Manchester United and
Everton. During the trials, Gleeson impressed the management of both clubs but was suffering the effects of lingering illness, which management took into account. After the initial trial, Everton offered Gleeson a retrial which ultimately ended without an offer being made. Although Manchester United did not offer a retrial, they thought highly of Gleeson and goalkeeping coach Richard Harris promised to recommend Gleeson to other English clubs for a place in their academies. Gleeson moved up to a higher division in 2008 by signing for
Team Wellington of the
ASB Championship, the national association football league of New Zealand, and spent the next two years with the club, featuring in 5 games in total.
Portland Timbers Gleeson was offered a trial with
Seattle Sounders FC of
Major League Soccer in 2010 but declined the opportunity in favor of a guaranteed contract offered by the former
USL incarnation of the
Portland Timbers in preparation for their promotion to
Major League Soccer. He was to train with the USL team but play for the team's
USL Premier Development League affiliate,
Portland Timbers U23s. In an interview with New Zealand media in April 2010, Gleeson stated, "I don't have a guaranteed spot but I'm in a really good position because I'm a youth player. I'll come in as the No3 goalie and try and work my way up from there", regarding his prospects of eventually making the transition from the Timbers-U23 team to
senior roster. In his first season with the club, Gleeson and the Timbers U-23 squad became
PDL Champions. To begin the season, Gleeson logged 15 saves in three shutout performances to help the Timbers U-23s record wins over
Tacoma Tide,
Yakima Reds, and
Spokane Spiders in a one-week period, earning him team of the week honors. By finishing with a 20–0–0 record, the team became the PDL's first undefeated championship team. After training with the team throughout pre-season, Gleeson formally signed with the
Major League Soccer Portland Timbers on 17 February 2011. He made his MLS debut on 26 March 2011 against
Toronto FC as a second-half substitute for an injured
Adin Brown. Despite starting the season as the club's third-string goalkeeper, Gleeson started the first MLS home game in Timbers history and played all 90 minutes in the Timbers' 4–2 win over the
Chicago Fire. Three days later, Gleeson pushed a difficult shot off the post in the 90th minute which would have given
FC Dallas the game-tying goal. This save gave Gleeson his second MLS save of the week in five weeks. On 18 February 2014 Gleeson was loaned out to
Sacramento Republic FC as part of the loan agreement between MLS and USL Pro. He made 17 regular season appearances for Sacramento on this loan spell, allowing less than a goal per game, and posted the shutout in their 2–0 victory over
Harrisburg City Islanders in the
USL Pro Championship. Despite starting the 2016 season as a backup, Gleeson was quickly thrown into action when starter
Adam Larsen Kwarasey suffered a torn hand ligament. Over the first half of the season, Gleeson impressed as a #1 and earned the starting job over Kwarasey. Through 14 starts while Kwarasey was injured, Gleeson allowed 18 goals, while posting 70 saves and the Timbers' only 3 shutouts for the year. In 2018, he had surgeries on his right shin due to stress fractures. Due to complications, he had eight further surgeries, which ended his career. In 2020, Gleeson officially sued the Timbers physicians for malpractice and negligence. A jury in 2025 ruled in favor of Gleeson and he was awarded $20.6 million in damages. ==International career==