Born in England, he represented the Republic of Ireland 36 times at full international level, scoring 9 goals, and made their squad for the 2002 FIFA World Cup.

[3][7] He began his career at Crystal Palace of the Premier League, making his debut on 10 May 1998 as an 82nd-minute substitute for Neil Shipperley, and scoring the injury-time winner over opponents Sheffield Wednesday.

[8] At the start of the 1998–99 season, Morrison appeared in the second leg of the UEFA Intertoto Cup third round against Samsunspor, eventually losing 4–0 on aggregate.

[17] Financial difficulties meant that Crystal Palace were unable to make new signings for the 1999–2000 season and relied on youngsters such as Morrison and Hayden Mullins and veterans such as Andy Linighan as they successfully battled against relegation from the First Division.

[13] At the start of the 2000–01 season, Morrison, however, was placed on a transfer list by new Manager Alan Smith despite signing a four–year contract with Crystal Palace.

[38] Over the summer transfer of 2002, Morrison was linked a move away from Crystal Palace, with Premier League clubs, including Birmingham City, were interested in signing him.

[40] With a tricky relationship becoming clear between Morrison and Trevor Francis, then Palace manager, it was Birmingham City who fought and won his signature, for £4.25 million, in exchange for Andrew Johnson.

[41] However, his start to his Birmingham City's career suffered a setback when he sustained a groin injury during the club's pre–season that saw him miss two matches.

[50] In his first season at Birmingham City, Morrison became a first team regular, becoming the club's first choice striker but struggled somewhat in the top league, scoring only six goals in twenty–nine appearances.

[58] Since returning from injury, Morrison rotated in and out of the starting line–up, but around the same time, he began to form a decent strike partnership with Emile Heskey.

[61] It wasn't until on 21 November 2004 when Morrison returned to the starting line–up against Blackburn Rovers and played 65 minutes before being substituted, as Birmingham City drew 3–3.

[71] He claimed that a large part of his decision to return (besides his love for the club) was, ironically, due to being able to play alongside Andrew Johnson, the man Birmingham had originally swapped to get Morrison.

[75] Since returning to the club, Morrison had a successful first season back at Crystal Palace, alternating with former strike-partner Dougie Freedman in playing alongside Johnson.

[78][79] Having aimed at personal target to get back to the Premier League, he later helped Crystal Palace qualify for the Championship Play–Offs despite missing one match, due to a broken jaw.

[87] But Crystal Palace's chairman Simon Jordan responded to the claims that the pair had not fallen out, with Taylor having dealt with Morrison over their differences.

[96] However, Morrison's target to score his 100th goal in his Crystal Palace's career became an albatross round his neck, and manager Peter Taylor dropped him from the starting line-up for several games.

[115] Since joining Coventry City, Morrison quickly became a first team regular for the side, forming a partnership with Freddy Eastwood.

[130] At the end of the 2009–10 season, Morrison said he was keen to sign a new contract with the club, but Coventry City told him he was surplus to requirements and he was subsequently released.

[139][144] But following his return from a loan spell at Milton Keynes Dons, Morrison made his first appearance for Sheffield Wednesday for the first time in a month, against Wycombe Wanderers on 29 October 2011, coming on as a 76th-minute substitute, as the club won 2–1.

[159] On 16 July 2012, Morrison signed a two-year deal with League One side Colchester United following his release from Sheffield Wednesday.

He celebrated the goal by running the length of the pitch with his hands cupped behind his ears to taunt the Sheffield United fans who, throughout the game, had been doing likewise to the striker for his connections with their city rivals, Wednesday.

[164] Joe Dunne took over as the U's boss at the end of September and immediately brought in Jabo Ibehre on loan from Milton Keynes Dons, with the loanee displacing Morrison from the starting eleven and consigning him to the bench.

[166] The impressive form of Ibehre ensured that Morrison only started four more games for the U's until March, when injury to Freddie Sears created a hole in attack.

This was coupled with Ibehre receiving a three-match suspension[167] and Morrison went on to spearhead the U's attack once more, providing crucial experience in Colchester's bid for League One survival.

[170] Following the absence of Ibehre, he began to appear in the starting eleven in a number of matches for Colchester United, while also trying to score goals on a regular basis.

[183] Morrison played 25 league matches in what remained of the season,[184] and was then released,[185][186] but rejoined the club on a short-term deal ahead of the 2015–16 campaign.

[193] Morrison was released by Exeter City at the end of the 2015–16 season and duly signed for Southern Premier Division side Redditch United in June 2016.

[208] Morrison then scored his second national goal, in a 3–0 win against Denmark on 27 March 2002 when "his pace and directness continued to cause the Danish defence problems and, in injury time Colin Healy and David Connolly combined to leave him a chance which he side-footed in".

He scored three goals in the qualifying campaign, but Brian Kerr's side finished fourth in a tight group that included Switzerland, France and Israel.

[213][216] At one point during the qualifying campaign, Morrison accused Alexander Frei of making a racist comment to him during the Switzerland and Republic of Ireland match on 9 September 2004.