Keene is a product of the Portsmouth youth scheme. After making his way through the ranks – including a successful ‘work experience’ loan at A.F.C. Newbury – he was loaned to Football League Two club Kidderminster Harriers, making his debut in a 2–0 defeat to Bristol Rovers. Keene was the Man of the Match for the visitors. He played five more games for Kidderminster, excelling during his loan period.
On 1 January 2016, Bidvest Wits of the South African Premier Division announced that Keene had signed for them. On 14 May 2018, it was announced that he would join SuperSport United for the 2018–19 season.