Career
Arsenal
A product of the Arsenal Academy, Henderson came to prominence during the Gunners" 2008-2009 FA Youth Cup, 2008-2009 Premier Academy League and 2009-2010 Premier Academy League wins. Henderson was named on the bench for the away trips to Wigan and Blackburn near the end of the 2009-2010 season but did not make an appearance. Arsène Wenger later stated after the match that he expects Henderson to be a future player for the first team
During pre-season, he damaged his knee ligaments.
Arsène Wenger later said that he would be out for a minimum of six months. In March 2012 he played his first game in eight months in a behind closed doors match against Reading.
In September 2012, Henderson went on a 3-month loan to Coventry City, making his debut in a 2–1 home defeat to Carlisle United. However, Henderson loan spell at Coventry City was marred by spell on the substitution bench and injuries.
Henderson was released by Arsenal after the end of the 2012-2013 season, after failing to agree a new deal with the club
Hull City
After impressing manager Steve Bruce during two reserve matches, Henderson was signed by Hull City on 24 September 2013 on a free transfer and was given the number 30 shirt. On 27 March 2014, Henderson went out on loan to Stevenage for the rest of the season. After featuring on the bench four times, Henderson made his debut for the club on 12 April 2014, where he made his first start, as Stevenage lose 3–2 to Colchester United.
Henderson would added two more appearance for Stevenage.
Unfortunately, Stevenage were relegated to League Two and he returned to Hull City. At the end of the 2013-2014 season, Henderson was released by the club upon the expiry of the contract.
Crawley Town
After being released by Hull City, Henderson joined Crawley Town for free on a one-year contract. Henderson made his debut in the opening game of the season, where he set up the only goal in the game as Crawley Town beat Barnsley 1–0.
However, Henderson was placed on the transfer listed by Manager John Gregory after being on the bench.
Nevertheless, Henderson remained in the first team, until an ankle injury in the 2–2 draw against Milton Keynes Dons kept him out for the remainder of the season. Having spoke to new manager Mark Yates in June 2015, Henderson agreed to a new six-month contract with the club Grimsby Town
On 25 November 2015, Henderson joined National League side Grimsby Town, on loan until January 2016.
Having previously spending a week on trial at Scottish Premiership side Inverness Caledonian Thistle.
Following his release by Crawley, Henderson signed a deal until the end of the 2015-2016 season. He represented England at youth level but then switched to Republic of Ireland and has represented them at U-19 level
In March 2011 made his debut appearance for the Irish national Under-21 team