Lukas Manuel Klostermann (; born 3 June 1996) is a German professional footballer who plays as a right-back or centre-back for Bundesliga club RB Leipzig and the Germany national team. Career VfL Bochum Born in Herdecke, Germany, Klostermann began playing football when he was "five or six years old". He played for various youth teams at FSV Gevelsberg, SSV Hagen and VfL Bochum. While at FSV Gevelsberg, he played in various positions before settling in defence at VfL Bochum. After progressing through VfL Bochum's youth system, Klostermann was promoted to the U19 side and then VfL Bochum II. While at VfL Bochum's youth system, Klostermann captained the U17 and U19 side. At some point, he signed a contract with the club, keeping him until 2015. He made his debut for the club, coming on as a second–half substitute, in a 2–0 win over VfR Aalen on 14 March 2014. At the time of his debut, he appeared at just 17 years and 283 days. Towards the end of the 2013–14 season, Klostermann pushed Paul Freier out of the first team over a right–back position. His handful of first team appearances resulted him being named the club's Player of the Month for May. At the end of the 2013–14 season, he made nine appearances for the side. By the end of June, it was revealed that Klostermann had yet to sign a professional contract, leading to a start of negotiating. In August 2014 it was announced that Klostermann and VfL Bochum had failed to reach an agreement regarding the extension of his contract. RB Leipzig Subsequently, he did not play another game for Bochum and on 22 August 2014 it was announced that he would transfer to RB Leipzig. He signed for Leipzig on a four-year deal until 2018. Shortly after joining RB Leipzig, Klostermann was assigned to the U19 and RB Leipzig II. He made his RB Leipzig debut against Erzgebirge Aue in the second round of DFB-Pokal on 29 October 2014 but scored an own–goal and helped the side win 3–1 later in the game. It wasn't until on 12 December 2014 when he made his league debut for the club, where he came on as a late substitute, in a 1–0 win over Greuther Fürth. He then made his first start for RB Leipzig on 6 February 2015, in a 2–2 draw against Erzgebirge Aue. Towards the end