Hoffer made his Fortuna Düsseldorf debut on 30 August 2013, playing 30 minutes after coming on as a substitute, in a 4–2 loss against Arminia Bielefeld. On 9 December 2013, he scored his first goal for the club, in a 1–0 win over 1. FC Kaiserslautern. This was followed up by scoring two more goals against Energie Cottbus and 1. FC Köln. Since joining Fortuna Düsseldorf, Hoffer found himself in a competitions with strikers such as Charlison Benschop and Aristide Bancé which saw him placed on the substitute bench in the first half of the season. By the second half of the season, Hoffer managed to regain his first team place under the new management of Oliver Reck. He went on to score six more goals, including scoring four goals in three matches between 26 April 2014 and 11 May 2014 against Erzgebirge Aue (twice), Karlsruher SC and 1. FC Kaiserslautern. In his first season at Fortuna Düsseldorf, Hoffer made 24 appearances scoring 9 times.