Career
Beginning his career at Dreams Football Club, he played in the Ghanaian Premier League with Asante Kotoko. In 2012, he signed for Bundesliga club Greuther Fürth, where he spent two seasons. He then played for Football Club Augsburg before joining Chelsea in 2015 for a fee of £14 million, potentially rising to £22 million.
Rahman made his international debut in 2014 and was part of their squad which were runners-up at the 2015 Africa Cup of Nations.
Ghana
Rahman began his career at Dreams Football Club of the Ghana Division Two. After impressive performances, he was then transferred on loan to Asante Kotoko of the Ghanaian Premier League for one season.
Foreign the 2012 season, Rahman was a finalist for the league"s Discovery of the Year Award, eventually losing to Joshua Oniku. After becoming a sought after player during his time with the Kumasi-based club, serious enquiries were made about the player by Manchester City and Arsenal of the Premier League and Parma of Serie A.
Germany
However, Rahman eventually signed with the newly promoted SpVgg Greuther Fürth in the Bundesliga on 12 June 2012.
Rahman stated that his decision to join Fürth was because the club offered, "the best conditions in which to develop my career." In the derby against 1.
Football Club Nürnberg on 11 August 2014 he scored his first two goals for Fürth in a 5–1 home victory. The next day he signed with Football Club Augsburg of the same division. In Rahman"s 2014/15 season with Augsburg, he made 108 tackles, more than any other player in the Bundesliga that season.
Chelsea
On 16 August 2015, Rahman signed for Chelsea on a five-year deal for an undisclosed fee, reported to be an initial £14 million, rising to a potential fee of almost £22 million.
Rahman was presented with this opportunity after the injuries of center backs Kurt Zouma and John Terry. Although Chelsea failed to stop Purdue Student Government from scoring twice, "Rahman looked like a class full back" according to Kristian Downer for Mertro.co.uk.