On 1 August 2010, during Borussia Mönchengladbach's arranged friendly match versus Liverpool as part of their 110th anniversary celebrations at Borussia Park, Matmour took advantage of some poor play by Daniel Ayala inside the area and produced a powerful finish in the eighth minute. They won the contest thanks to Matmour's goal, with the final score being 1–0. At the start of the 2010–11 season, he suffered three injuries in the first four months to the season. It wasn't until on 6 November 2010 when Matmour returned to the first team from injury, coming on as a late substitute, in a 3–3 draw against Bayern Munich. However, his return was short–lived when he missed one match, due to a flu in mid–January, but quickly recovered and returned to the first team against Bayer Leverkusen on 23 January 2011. In a follow–up in a league fixture against Eintracht Frankfurt on 30 January 2011, Matmour came on as a substitute for Mike Hanke in the forty-sixth minute and came close to scoring with a header which bounced off the top of the crossbar but he set up the only goal scored in the encounter which was a cross from the left side to Igor de Camargo, who put the ball away inside the far right post, as the club won 1–0.Since returning from injury, Matmour rotated in and out of the starting line–up, although he remained in the first team for the remainder of the season. Matmour played in both legs of the league’s relegation play–offs against VfL Bochum as a late substitute, as Borussia Mönchengladbach won 2–1 on aggregate and retained its Fußball-Bundesliga spot for the 2011–12 season. At the end of the 2010–11 season, he went on to make a total of 23 appearances in all competitions. Following this, Express reported that Matmour could be leaving the club.