フェリックス・シュトルム
In early Autumn 2013, it was announced by Eddie Hearn that Barker's first defense of the IBF Middleweight Title would be against veteran German boxer Felix Sturm at the Porsche-Arena, Stuttgart, Germany on 7 December 2013. Felix Sturm dropped and felled Barker twice in the second round before his corner threw in the towel, Barker having dislocated his hip from the first knockdown. Following the fight, Barker spoke about retirement due to a recurring hip injury, for which he had received surgery a few years earlier, and eventually in 2014 he announced his retirement from boxing.