Matmour made his 1. FC Kaiserslautern debut, where he started the whole game, in a 1–0 win over SC Paderborn in the opening game of the season. Then, on 3 August 2013, Matmour scored his first goal for the club, in a 7–0 win over Neckarsulmer SU in the first round of DFB-Pokal. Since making his debut, he quickly established himself in the first team at 1. FC Kaiserslautern. Matmour then played in the right–back position for the first time after the club was low of right–back position, in a 1–0 loss against SV Sandhausen on 14 September 2013. A week later on 25 September 2013, he scored for the second time in the tournament in the second round of DFB-Pokal, in a 3–1 win over Hertha BSC. It wasn't until on 8 November 2013 when Matmour scored his first league goal for 1. FC Kaiserslautern, in a 4–0 win over FSV Frankfurt. His fourth goal of the season came on 23 February 2014, in a 2–1 loss against VfR Aalen. Since the start of the 2013–14 season, he started in every matches for the club until he sustained a thigh injury while training, resulting in him missing one match. Matmour returned from injury in a match against Arminia Bielefeld on 26 March 2014, coming on as a second half substitute, in a 1–1 draw. However, his return was short–lived when he was suspended for picking up five yellow cards this season. His return from suspension later saw him contribute for 1. FC Kaiserslautern by setting up two goals, in a 4–0 win against Dynamo Dresden and then scored his fifth goal of the season, in a 4–2 loss against Fortuna Düsseldorf, as the club finished fourth place in the league. At the end of the 2013–14 season, Matmour finished his first season at 1. FC Kaiserslautern, making 37 appearances and scoring 5 times in all competitions.