He played only four Premier League matches for Wigan and returned to Scotland, spending three seasons troubled by injury at Rangers.
He made his debut aged 17, away to Stirling Albion in the second round of the Scottish Challenge Cup on 24 August 1999, playing the entirety of a 1–1 draw with his team eventually losing in a penalty shootout.
His first and only goal for the club came on 17 March 2001 during a home league match against Queen's Park which Arbroath won 2–0, confirming the scoreline in the 81st minute by finishing a Kevin Heenan corner kick.
[8] His debut came on 22 April in a 1–0 defeat away to Celtic, replacing Kevin McKenna for the final five minutes,[9] and he played three more matches (all starts) for the remainder of the Scottish Premier League season.
[12] On 24 September 2003, Webster scored his first European goal in the first leg of the first round of the season's UEFA Cup, confirming a 2–0 win over Bosnia's FK Željezničar Sarajevo.
Webster made a mistake which nearly gave the Portuguese club the lead, but later opened a 3–1 win by heading in from Mark de Vries' knock-down at close range.
He was given a straight red card on 11 December away to Inverness Caledonian Thistle, when he pushed Graham Bayne into the dug-out in the 33rd minute, but Hearts drew 1–1.
[16] On 23 April 2005, Webster equalised in the 88th minute of the Edinburgh derby away to Hibernian, putting in Paul Hartley's free kick for a 2–2 draw at Easter Road.
[17] During his time with the Jambos he established himself as a regular at the heart of defence playing alongside club captain Steven Pressley and also became a fixture in the Scotland national team.
He was a regular for the side and made 184 appearances for the Jambos but in 2006 he was left out of the match against Dundee United because of a disagreement over contracts, with chairman Vladimir Romanov, who later suggested to many that Webster would leave soon.
This enabled him to cancel his contract with Hearts in the third year of a four-year deal, with the proviso that he join a club in a foreign country and that sufficient notice be given to his former employers.
[21] On 30 January 2008, Court of Arbitration for Sport ruled that Heart of Midlothian Football Club were to be awarded £150,000 for Webster's breach of contract.
[22][23] Webster made his Wigan debut in a league match in a 4–0 win against Manchester City at the JJB Stadium on 21 October 2006, replacing Fitz Hall at half time and receiving a booking.
He made his debut in a post-season friendly match in May 2007, against LA Galaxy at the Home Depot Center, coming on as a substitute for Karl Svensson.
[31] He made his debut against Coventry City at the Ricoh Arena five days later, replacing Louis Carey in the 64th minute of a 3–0 victory.
[40] He made his debut the following day, playing the full 90 minutes as Coventry won 5–4 against former team Bristol City in the first match at their temporary home of Sixfields in Northampton.