Walker for many years was the number one goalkeeper for Tottenham Hotspur, starting out with them as a trainee and having two loan spells, for Ipswich Town and Oxford United. Walker made 312 appearances for Tottenham Hotspur and won the 1999 League Cup after beating Leicester City 1–0 at the old Wembley Stadium. Walker handed in a transfer request in September 2000 after losing his place in the first team to Neil Sullivan. He played his final game for Spurs against West Ham United on 31 January 2001.
Leicester City
Walker signed a four-year contract with Leicester City in July 2001 for a fee of £2.5 million, rising to £3 million depending on appearances. His first season at the club ended in relegation to the First Division, which he felt may have ruined his dreams of an England call-up for the 2002 World Cup. Walker had an impressive season with Leicester as they regained promotion to the Premier League, earning his first England recall in six years in May 2003. He struggled with life in the Premier League, particularly in a match against Aston Villa at the Walkers Stadium on 31 January 2004, in which he conceded five goals in 18 minutes. Walker put up such a poor display in the match that he was confronted by a Leicester fan who ran onto the pitch, telling him he "didn't think he was fit to be a Premiership player." On 10 February 2004, Walker scored a bizarre own goal in a match against Bolton Wanderers to give them a 1–1 draw at Leicester. Despite comfortably saving Kevin Davies' shot, he lost grasp of the ball as it crawled over the goal line. He did make a comeback performance in a goalless home draw against Wolves on 28 February, putting up a "world-class save" to deny Kenny Miller. Walker pledged to stay at Leicester despite their relegation from the Premier League in the 2003–04 season. He was released from Leicester City on 6 May 2005, after the club could not afford him a new contract. Walker spent four years at Leicester.
Bolton Wanderers
Walker joined Bolton on a one-year contract. Walker was the goalkeeper for Bolton's first ever European match away from England against Bulgarian team Lokomotiv Plovdiv, which was also his debut.
International career
Walker was capped by the England national team four times, making his debut in 1996 against Hungary. His most infamous game was against Italy in a qualification match for the 1998 World Cup where he is widely believed to have been at fault to a Gianfranco Zola strike. England lost this game to Italy 1–0 at Wembley Stadium. He backed up David James at Euro 2004 but was overtaken by others in the pecking order. Despite Walker's club Leicester suffering relegation from the Premier League, he played his first England match in seven years as a 61st-minute substitute for Paul Robinson in a 6–1 win over Iceland on 5 June 2004, which was also his last international.
Managerial career
On 14 March 2011, Walker was appointed as manager of Bishop's Stortford who were playing in the Conference South. In April 2012, Walker joined his former Bolton teammate Nicolas Anelka at Chinese Super League side Shanghai Shenhua and became their goalkeeping coach. On 2 January 2014, Walker became the goalkeeping coach of Shanghai East Asia, another Super League team in Shanghai. On 15 May 2014, Walker signed a new contract with Shanghai East Asia, keeping him at the club until the end of 2017 season. Walker continues to coach the 1st team goalkeepers at Shanghai SIPG FC. Walker has produced two national team goalkeepers for China,Wang Dalei from Shanghai Shenhua in 2012/13 and Yan Junling from Shanghai SIPG in 2014/15,both continue to be in the national squad with Yan Junling who is still coached by Walker the China number 1 goalkeeper. In the 2018 season Walker was the goalkeeper coach when Shanghai SIPG won their first league title ever.
