A product of the Leicester City academy, Schlupp made his senior debut in 2011 following a brief loan to Brentford in League One.

Schlupp was born to Ghanaian parents in Hamburg, Germany, on 23 December 1992, and raised mostly in England after his family moved there when he was young.

Schlupp joined Brentford on a one-month loan on 14 March 2011, declining a call up to the Germany Under-19 squad in order to complete the move.

[10] Schlupp earned a start in Brentford's next match and proved himself once more by scoring a header from a Lewis Grabban cross against Sheffield Wednesday in a 3–1 victory.

[3] In his first competitive senior appearance for the club he scored a hat-trick against Rotherham United in the League Cup first round on 9 August.

Schlupp opened his goalscoring account for the 2013–14 season, rounding off a 3–1 away win to against Millwall on New Year's Day 2014 with smart finish through the goalkeeper's legs on his weaker foot.

Following regular left-back Paul Konchesky receiving a three-match suspension for a red card against East Midlands rivals Nottingham Forest, Schlupp found greater opportunities at the back of the Leicester side, putting in highly rated performances against Ipswich Town and Charlton Athletic.

On 16 August 2014, Schlupp made his Premier League debut as a second-half substitute against Everton on the opening weekend of the season.

Schlupp scored his second goal of the season on 29 November, in the 2–3 defeat against Queens Park Rangers before adding his third in the 2–2 draw against Liverpool on 1 January 2015.

[31] Schlupp scored an equaliser within 48 seconds of coming on as a substitute in a 2–2 draw against former club Leicester City on 3 October 2021; it was his first goal under manager Patrick Vieira.

[40] Schlupp made his Ghana debut against Gabon on 15 November, coming on as a late substitute for Prince Tagoe.

[41] In April 2014, it was reported that The Black Stars' coaching team are believed to have watched Schlupp play with a view to taking him to the 2014 FIFA World Cup in Brazil following a string of impressive performances for Leicester.

[42] He earned his fourth cap as a late substitute in Ghana's 3–1 win against Togo in the Black Stars' last African Cup of Nations qualifier on 19 November 2014.