Born in Liverpool, McGreal began his career with local club Tranmere Rovers at the age of 17 and moved from Warwick Rimmer's youth-team to the first-team set-up under John King in 1990.
[9] He scored his second goal with the winner in a 2–1 victory over Tottenham Hotspur on 12 January 2002,[12] but he couldn't help halt the side's slide down the league as they finished the 2001–02 season in 18th-place and were relegated back to the First Division.
[16] He made his debut for the side on 7 August 2004 in a 1–1 home draw with Sheffield United, before scoring what was to be his only goal for Burnley in a 3–0 win over Crewe Alexandra at Turf Moor on 11 September.
[20] After leaving Burnley at the end of the 2006–07 season, McGreal returned south, briefly joining Championship side Colchester United on trial, but manager Geraint Williams decided against offering the player a contract.
[30] The club signed a number of players in preparation for the 2016–17 season, including defenders Luke Prosser (who he appointed as captain[31]) and Lewis Kinsella; midfielders Brennan Dickenson, Craig Slater and Doug Loft; and forwards Courtney Senior, Kurtis Guthrie, and Denny Johnstone.
[36] After an eleven-game winless run, McGreal's side went undefeated in December, earning ten points from a possible twelve which propelled Colchester up the League Two table away from the relegation zone.
[40] McGreal released eight players, whilst also losing top-scorer Chris Porter, who left on a free transfer to sign with Crewe Alexandra.
[32] Colchester got off to a poor start, but improved and collected ten points from five games to earn McGreal another Manager of the Month nomination in October.
[49][50][51] Colchester enjoyed a strong first half of the campaign, and a 1–0 win at Milton Keynes Dons saw them head into Christmas in the automatic promotion places.
[53] However the promotion campaign faltered, and despite beating champions Lincoln City on the final day, Colchester ended in eighth-place, a point outside the play-offs.
[55] However he lost a series of players who turned down new contract offers: Brennan Dickenson, Sam Saunders, Rene Gilmartin and Dillon Barnes; whilst Frankie Kent, Sammie Szmodics and Kane Vincent-Young were sold on to other clubs.
[56][57][58][59][60][61] He signed a number of young players to replace those that had departed: Kwame Poku, Luke Gambin, Omar Sowunmi, Jevani Brown, Cohen Bramall and Callum Harriott.
[32] More senior players Paris Cowan-Hall and Dean Gerken were also signed, whilst Theo Robinson joined on a season-long loan from Southend United.
[32] Having made an indifferent start to the 2019–20 League Two season, Colchester entered the play-offs for the first time with a 3–1 win at Leyton Orient on Boxing day.
[65] However the club announced that 16 players would be released at their end of their contracts, with chairman Robbie Cowling admitting that he "would have been determined to re-sign" Brandon Comley, Ryan Jackson, Frank Nouble and Luke Prosser in normal circumstances.
[66] Colchester lost out to Exeter City after extra-time in the play-off semi-finals and McGreal was subsequently dismissed by the club on 14 July 2020 as Cowling felt that "significant changes are required that will be best served with a new head coach".
[71] On 2 December 2021, McGreal returned to Ipswich Town, a club he made 150 appearances for, in a coaching role that would see him work with the U23s and Development squads.