Diouf returns to England after two and a half seasons at the HDI Arena, having signed for Hannover from Manchester United FC in January 2012. The 26-year-old spent the 2010/11 campaign on loan at Blackburn Rovers FC.
The Dakar-born striker scored 26 goals in 57 outings for die Roten and though injuries restricted him to just 19 Bundesliga appearances in 2013/14, Diouf ended the campaign as second-top scorer behind Szabolcs Huszti.