Ben Khalifa made his debut with Grasshopper in the Swiss Super League on 7 March 2009, at the age of 17, where he played the last 11 minutes in the game against FC Sion.
On 19 February 2010, he signed a four-year contract with VfL Wolfsburg of the German Bundesliga and joined his new club on 1 July 2010 [REF].