Matthew James Green was born in Bath. He came on a one-month loan from Cardiff City in November 2007, scoring on his debut at Kidderminster. Unfortunately, he broke his collar bone three minutes into his third game, at Northwich Victoria, and returned to Wales. Following his recovery, Oxford signed him again until the end of the season, during the January 2008 transfer window. He was Darren Patterson`s prime close-season target in 2008, but after agreeing to sign for the club, instead he followed the pound signs and joined Torquay instead. He rejoined Oxford, under Chris Wilder's management, on a season-long loan in June 2009. On 15 September he played for England C in their 1-1 draw in Hungary. Green scored United's first goal in the Conference play-off final win over York in May 2010. At the start of June 2010 Green signed a two-year deal with Oxford, joining from Torquay for an undisclosed fee. He moved to Cheltenham in January 2011 on loan until the end of the season. At the start of the following season he signed for Mansfield Town on loan, joining the Stags permanently in January 2012.