UCD Born in
Dublin, Dicker began his career at
League of Ireland side
UCD. He joined from his local junior club
Cherry Orchard and was gradually introduced into the first team through substitute appearances towards the latter end of UCD's successful 2004 First Division campaign. Dicker progressed his way into a regular starting position the following season and successfully partnered
Tony McDonnell in central midfield for the 2005 and 2006 Premier Division seasons. During his time at UCD he earned underage honours for Ireland at under-19 and under-21 level. In the 2006 League of Ireland close season he spent a loan spell at
Championship side
Birmingham City, but he never made it past the reserve team. He made his debut for the Birmingham City reserves against
Stoke City Reserves, which Birmingham won 3–0. The Birmingham reserve team coach,
Keith Bertschin, described Dicker as a "very decent player. He's a good technical player, who can see and put in some lovely weighted passes and is decent with both feet".
Stockport County Dicker was signed by manager
Jim Gannon for
Stockport County on 29 May 2007, for a fee of just £40,000, signing a contract until 1 July 2010. He played a regular part in Stockport's 2007–08
League Two campaign and took part in a promotion for the second time in his career as County successfully negotiated their way into League One via the playoffs. Dicker was a fan favourite during his time at Stockport for his passing ability and off the ball work rate. Dicker scored his only goal for Stockport in November 2008, opening the scoring in a 5–0 win in an
FA Cup first-round tie at home to
Yeovil Town.
Brighton & Hove Albion in 2011 On 26 March 2009, Dicker joined
League One side
Brighton & Hove Albion on loan for the remainder of the
season. He made nine appearances for the Seagulls, scoring one goal, during this spell. On 25 June, he joined Brighton on a free transfer, signing a two-year contract. On 28 April 2011, having helped Brighton secure promotion to the
Championship, Dicker was rewarded with a two-year contract extension. He was released when that contract expired at the end of the 2012–13 season.
Rochdale On 13 September 2013, Dicker joined
Rochdale on an initial five-month deal.
Crawley Town (loan) On 23 January 2014, Dicker joined
Crawley Town for the remainder of the
2013–14 season.
Carlisle United On 27 June 2014, Dicker signed a two-year deal with League Two side
Carlisle United.
Kilmarnock On 1 February 2016, Dicker moved to
Scottish Premiership club
Kilmarnock, signing an eighteen-month contract. He made his debut in a
Scottish Cup tie away to
Rangers five days later. In early February 2021, Dicker was asked to help take temporary charge of the Kilmarnock first team alongside
James Fowler and
Andy Millen following the departure of
Alex Dyer. He left Kilmarnock at the end of the 2020–21 season.
Return to Brighton Dicker returned to Brighton & Hove Albion on 2 July 2021, signing a deal to become a coach for
the U23s whilst being eligible to play as one of three over-age outfield players in the
Premier League 2. He made his first appearance since signing on 14 September, starting in the away trip at
Walsall in the group stage of the
EFL Trophy. He was shown a straight red card for a dangerous challenge on
Emmanuel Osadebe in the 1–0 loss. On 25 January 2022, Dicker announced his retirement from playing professional football. ==Coaching career==