Nigeria on 17 April 2002. In that same year he also played in defeats against Denmark, South Korea and South Africa as well as a 4–0 victory over Hong Kong. Coaching career Grimsby Town In June 2010 Stockdale signed a new deal with The Mariners, where he also became the club's youth team manager as well as staying on as a player. The club had not appointed a new youth team boss since promoting Neil Woods to first team manager following the sacking of Mike Newell in November 2009. Stockdale was kept on the playing records as well for the 2010–11 season and was handed a squad number to be used as cover for Peter Bore, Bradley Wood and Dwayne Samuels who were the club's other contracted players who are capable of playing in Stockdale's position. On 4 March 2011 it was announced that Stockdale and assistant manager Dave Moore would take caretaker control of the first team for the home tie with AFC Wimbledon on 5 March, following the sacking of Neil Woods. The game ended in a 2–1 victory for The Mariners in what was Moore's first managerial match in fifteen years and Stockdale's first ever game as a manager. On 23 March 2011, Stockdale and Moore relinquished managerial duties to the newly appointed duo of Paul Hurst and Rob Scott following 2 victories, 1 draw and 1 defeat. Stockdale continued to manage the youth team at the club until stepping down on 29 August 2012. Sunderland On 29 August 2012 Stockdale became a youth team coach of Premier League side Sunderland. In return Sunderland offered to take their first team squad for a pre-season friendly at Grimsby for the following summer. On 22 September 2013 Stockdale was appointed assistant to caretaker manager Kevin Ball, following the sacking of manager Paolo Di Canio. After Ball stopped working due to injury, Stockdale became the U21 team manager for the 2014–15 season. With four wins out of the final six games of that season, the team finished 4th in the Barclays U21 Premier League, just below Manchester United, Liverpool and Chelsea. Their unbeaten run, starting from March 2015, continued to the 2015–16 season and came to an end when they lost 0–1 to Reading in August. Stockdale then guided the team to another five wins and one draw against the likes of Manchester City, Southampton and Liverpool, which sent the