starting in a 1–1 draw against Kettering Town, scoring an own goal just before half-time. He scored his first goal for the club against one of his former employers, Alfreton, scoring the winning goal in a 2–1 victory. He made six appearances for the club in all competitions, scoring once. Oxford United After just a month at Stalybridge, Foster returned to the highest tier in non-League football, joining Conference National club Oxford United on 16 February 2007. He made his Oxford debut two weeks after signing for the club, starting in a 1–0 home defeat to Kidderminster Harriers. He played nine times during the club's 2006–07 campaign, scoring once in a 2–0 win over St Albans City at Clarence Park. At the end of the season, he signed a new one-year contract with Oxford, keeping him contracted to the club throughout the 2007–08 season. After playing just three times in the opening two months of the season, Oxford manager Jim Smith stated that Foster needed to "improve the way he leads his life" in order to "stand a chance" of getting back into the Oxford first-team. After this, Foster played regularly until the end of the season, although he was given a one match suspension following his sending off against Northwich Victoria in March 2008. At the end of the 2007–08 season, in which he made 39 appearances, he won Oxford's Supporters Player of the Year and Players' Player of the Year awards. As a result of his form, he signed a new two-year contract with the club on 29 July 2008. During the 2008–09 season, Foster continued to play regularly at centre-back for Oxford,. In Oxford's match against Wrexham on 21 August 2008, Foster was sent off after just 11 minutes for "denying Wrexham's Shaun Whalley a clear goalscoring opportunity". As a result, he missed the next two games, returning to the first-team against Ebbsfleet United on 30 August 2008, but was once again sent off, this time for a foul on Craig Stone. Consequently, Foster did not play again in the first-team for a month. He regained his place in Oxford's defence, and played regularly until the end of the season. He scored his only goal of the season in a 2–1 victory over Lewes in February 2009. Foster made 44 appearances for the club during the season, scoring one goal, as Oxford narrowly missed out on a