Career
As a player he was a midfielder from 1983 to 2002, notably in the Premier League from Blackburn Rovers, Leicester City and Sunderland. He also played in the Football League for Barnsley, Portsmouth and York City before finishing his career in Non-League with Gateshead. Agnew started his career at Barnsley, staying there for eight years after turning professional and playing more than 200 times.
He was sold to Blackburn Rovers for £700,000 in June 1991 — making him the Ewood Park club"s most costly signing at the time, just after wealthy owner Jack Walker bought the club
His spell at Blackburn was unsuccessful, only making four appearances before he joined Portsmouth on loan and then Leicester City permanently in the 1992-1993 season, when Rovers were in the new FA Premier League and Leicester were challenging for promotion from Division One. During his time at Blackburn, the club earned promotion to the new Premier League, but Agnew"s part in the success was a minimal one as the attention was focused on big-money new signings such as Mike Newell and Roy Wegerle and later Alan Shearer and Stuart Ripley.
One of Agnew"s most memorable nights in a Leicester City shirt was Thursday, 15 April 1993, when Leicester beat Millwall 3–0. Agnew scored and was sent official
Agnew "reacted angrily to a heavy challenge by Andy Roberts.
At least a dozen players jostled each other as police, stewards and the respective managers tried to restore order. Agnew, who had already been cautioned, appeared to lash out at a Millwall player, leaving Mr Parker no option other than to reach for red. Agnew spent the 2001-2002 season playing for Gateshead, where he finished his playing days.
In February 2002 Agnew moved into coaching, becoming assistant manager of Gateshead to Gary Gill.
Both he and Gill resigned from Gateshead after the playing budget was cut in early October 2002. Agnew continued his coaching at the Middlesbrough Academy and then joined Leeds United as Reserve Team Manager in 2004.
Agnew left the club to become assistant manager at Hartlepool United on 23 June 2005. However, in 2006, Agnew quit his position at Hartlepool and rejoined Leeds as Under 18"s manager.
He rejoined Middlesbrough as reserve team coach on 23 January 2007.
He was promoted to assistant manager on 7 July 2008, following the departure of Steve Harrison. On 18 October 2010 he was put in temporary charge of first team matters following the resignation of Gordon Strachan. On 29 June 2012 it was announced that Agnew had taken up the post of assistant manager at Hull City.
On 23 December 2014, it was announced that Agnew had joined Middlesbrough as assistant head coach.