May 2008. Crystal Palace Before signing for Crystal Palace, Oster had a trial spell at Championship rivals Derby County. Oster signed an initial six-month contract for Crystal Palace on 11 August 2008, which was extended by a further 18 months. He scored on his debut against Hereford United in the League Cup. Doncaster Rovers Oster left Crystal Palace in the summer and joined Doncaster Rovers on a six-month contract. Oster made his Doncaster debut on 8 August 2009, coming on as a second-half substitute against Watford. He extended his contract in January 2010 to keep him at the club until the end of the 2009–10 season. He scored his first goal for Doncaster against Peterborough United on 16 March 2010. Due to his impressive form in the 2009–10 season, Rovers offered Oster the opportunity to renew his contract with the club. Oster agreed and committed to Doncaster for a further two years. Oster was an ever present for Doncaster in the 2010–11 season after topping the Rovers' appearance chart in mid April with 38 starts. In May 2012, Oster was released by the club after the expiry of his contract. Barnet On 7 September 2012, Oster signed for Football League Two club Barnet. On 19 October 2012, he scored his first goal for Barnet, scoring the third goal in a 4–0 win against Northampton Town. Oster was released by manager Edgar Davids at the end of the season following Barnet's relegation from League Two. Gateshead On 20 September 2013, Oster signed for Conference Premier club Gateshead on non-contract terms, the move being his first into Non-league. He made his debut the following day as a second-half substitute against Tamworth. He scored his first goal for Gateshead on 21 December 2013 in a 4–2 defeat at Luton Town. International career Oster made his debut for Wales as an 18-year-old in 1997, coming on as an injury-time substitute for Robbie Savage in a World Cup qualifying defeat in Belgium. Oster played intermittently for the national side between 1997 and 2004, accumulating 13 caps, though only six of these came in competitive games. Oster did not play in any games under John Toshack following his appointment in November 2004, his last cap for Wales being the 2–2 draw with Northern Ireland in 2004 under previous boss Mark Hughes. Coaching career In September 2019, Oster was appointed as assistant manager of Whickham under manager