John Deehan joined Sheffield Wednesday's coaching staff in February 2014.
Deehan is vastly experienced within the game, having held a number of managerial and coaching positions.
Previously, he helped coach a Norwich City side to a surprise third place finish in the inaugural Premier League (season 1992-93), and was promoted to the manager's seat the following January when Walker moved to Everton. Norwich finished 12th in the Premier League in 1993-94 and started the following season reasonably well despite the (then) record English sale of Chris Sutton to Blackburn Rovers for £5 million.
After Norwich, Deehan began the 1995-96 season as Wigan Athletic's manager in the Football League Third Division. He achieved success in the role and after two seasons he guided them to the Division Three title and promotion to Division Two. After ensuring Wigan's survival in 1997-98, he became the assistant manager at Sheffield United and for one season worked under Steve Bruce.
After leaving Sheffield United, Deehan again worked with Bruce at Huddersfield Town, In the 1999/2000 season, after leaving Huddersfield, he returned to the Premier League with Aston Villa when he was appointed assistant manager to John Gregory in July 2001. In January 2002, Deehan was then named joint caretaker manager of Villa (with Stuart Gray) when Gregory resigned. When Graham Taylor was named Villa manager for the second time, he then parted company with the club.
In October 2003, John Deehan became Director of Football at Northampton Town, with Colin Calderwood working under him as team manager. Both Deehan and Calderwood were appointed to get the team promoted and they achieved this aim in the 2005-06 season. Both Calderwood and Deehan left the club at the end of the 2005-06 season, with Deehan moving to Lincoln City again as Director of Football. On 15 October 2007, it was confirmed that Deehan and Lincoln City manager John Schofield had left the club.
In November 2007, Deehan moving into a scouting role with Premier League side Bolton Wanderers who were looking for a number of ex-professionals to head their recruitment drive lead by former Everton manager Colin Harvey.
More recently, he returned to Carrow Road in January 2009, when he was appointed as Chief Scout of Norwich in part of the new management team alongside three of his former players - Bryan Gunn as First Team Manager, Ian Crook as first team coach and Ian Butterworth as Assistant Manager.
Following Gunn's departure at Norwich, in December 2009, he became Lee Harper's assistant at Kettering Town before joining Grimsby, assisting manager Neil Woods for the close of the 2009/10 season.
He later joined Plymouth during the 2011/12 campaign.