Marcell Jansen (German pronunciation: [maʁˈsɛl ˈjanzn̩]; born 4 November 1985) is a German former professional footballer who played as a left-back. He was well known for his accurate crossing and pace, despite his tall stature. A versatile player, Jansen primarily played as a full back or wing back on the left flank, but could also play as a left-winger.
Growing up in Mönchengladbach, West Germany, Jansen joined Borussia Mönchengladbach from local SV Mönchengladbach in 1993 and progressed through the ranks at the club's academy. It was not until 2003 when then-Mönchengladbach manager Ewald Lienen named him as an unused substitute in a Bundesliga fixture of the club in a 2–0 loss against Hannover 96 on 19 September 2003. Ironically, this turned out to be Lienen's final game in charge of Mönchengladbach and Jansen returned to the U19 side.
The start of the 2004–05 season saw Jansen playing for Borussia Mönchengladbach II in the fourth division under manager Horst Köppel. By the end of 2004, Jansen was given a first team opportunity under Dick Advocaat, who gave him his debut for the side. They lost 6–0 away against Hertha BSC on 4 December 2004. During the match, which saw Hertha BSC leading 5–0 in the second half, it went bad to worse when he gave away a penalty, resulting a successful penalty kick from Marcelinho Paraíba to score Hertha's sixth goal. Nevertheless, Advocaat continued using him in the first team following an injury to club captain Christian Ziege. On 28 January 2005, Jansen signed his first professional contract with the club, keeping him until 2008. He continued to be a first team regular at the club, playing as a left-back and because of this, he earned a call up for the Germany under-21 national team as well.
It was not until on 3 April 2005 when Jansen scored his first goal for Mönchengladbach in a 2–2 draw against VfL Bochum. In his first season, Jansen went on to make 18 appearances, scoring once, in the 2004–05 season despite competing with Filip Daems for the left–back position.
In the 2005–06 season, Jansen continued to be a first-team regular, playing in both left-back and left-midfield and his impressive performance earned him a call-up from the German senior team. Due to his good performance, Jansen signed a contract extension with the club, keeping him until 2009. After the start of the season, he started every match until he suffered a calf injury. After returning from injury, he scored his first goal of the season on 17 December 2005 in a 4–3 win over Eintracht Frankfurt. By April, Jansen began playing in left-midfield after Daems was used regularly at left-back. At the end of the 2005–06 season, Jansen went on to make 33 appearances and scored once in all competitions.
Following the 2006 FIFA World Cup, Jansen was linked with a move away from Borussia Mönchengladbach, with top-flight clubs in Germany keen on signing him. However, the club insisted on not selling him, stating that he was not for sale. Jansen started the 2006–07 season playing in the left-back, dispatching Daems in the process. Jansen remained in the left-back position until he suffered a knee injury in early October. After returning to training in January, he returned to the first team on 27 January 2007, in a 3–1 loss to Energie Cottbus. Jansen then scored his first goal of the season on 2 March 2007, in a 2–0 win over Arminia Bielefeld. At the end of the 2006–07 season, which saw the club relegated to the 2. Bundesliga, Jansen had made 24 appearances and scored one goal in all competitions.
In March 2007, Bayern Munich expressed interest in Jansen following his performance for both Borussia Mönchengladbach and the Germany national team. In May 2007, it was announced Jansen would move to Bayern in July 2007 for an approximate €10 million transfer fee. Despite fears from the media he would largely remain on the substitutes' bench, Jansen said he was not afraid to be on the substitutes' bench, insisting the move was an important step of his career.
Jansen made his Bayern Munich debut in a friendly match, coming on for Philipp Lahm, in the 46th minute of a 4–0 win over Swiss side FC Schaffhausen. Jansen scored his first goal in his Bayern career in a friendly match in a 13–0 win over FC 07 Albstadt on 15 July 2007. He made his Bundesliga debut for Bayern on the opening day of the 2007–08 season in a 3–0 win over Hansa Rostock. Soon after, Jansen suffered an injury in the club's training and was sidelined throughout August. It was not until on 15 September 2007 when he returned to the first team, in a 1–1 draw against Schalke 04. Jansen played in each match until he suffered ankle injury around November that kept him out for three months. Around January, Jansen returned to training to maintain his fitness. On 1 March 2008, he returned to the first team in a 1–0 win over Schalke 04. Despite suffering from another injury towards the end of the 2007–08 season, he remained in the left-back position as the season progressed. Bayern won the Bundesliga with Jansen making 33 appearances in all competitions.
In the 2008–09 season, Jansen found himself on the bench for Bayern's opening two matches of the new Bundesliga campaign after falling out of favour with manager Jürgen Klinsmann, due to their differences.
On 28 August 2008, Hamburger SV announced Jansen had signed a five-year contract until 2013 for an €8 million transfer fee. Two days after signing, he made his Hamburg debut in a 4–2 win over Arminia Bielefeld. After debuting, he was given a handful of first-team appearances and became a first-team regular, playing in midfield. However, in mid-October Jansen suffered a muscle injury that kept him out throughout the month. On 8 November 2008, he played again as second-half substitute in a 2–1 win over Borussia Dortmund. His first goals came on 22 February 2009, in a 2–1 win over Bayer Leverkusen. After suffering an injury which kept him out of play throughout April, Jansen scored on his return on 3 May 2009 in a 1–1 draw against Hertha BSC. In the 2008–09 season, Jansen made 40 appearances and scored 4 goals in all competitions.
At the start of the 2009–10 season, Jansen suffered a tore collateral ligament which kept him out for two months. After returning from injury, he scored his first goal on 8 November 2009 in a 2–2 draw against Hannover 96. By the end of 2009, Jansen added four more goals in all competitions, including three goals in three Bundesliga matches between 12 December 2009 and 16 January 2010, against 1. FC Nürnberg, Werder Bremen and SC Freiburg. A combination of the flu and a ligament tear restricted his first team appearances as the 2009–10 season progressed. During the 2009–10 season, Jansen made 28 appearances and scored 9 goals in all competitions.
In the 2010–11 season, Jansen began the season playing at left-back. He continued to play the role until he was plagued by injuries which kept him out for three months. Jansen returned on 29 January 2011 to the first team, coming on as a second-half substitute in a 2–0 loss against 1. FC Nürnberg. He scored his first goal of the season on 26 February 2011 in a 1–1 draw against 1. FC Kaiserslautern. However, he suffered a hip injury in training which kept him out for the rest of the season. Despite this, Jansen finished the 2010–11 season, making 17 appearances and scoring 2 times in all competitions.
Ahead the 2011–12 season, Jansen was linked with clubs such as Milan and VfL Wolfsburg. But Jansen made it clear that he was not leaving the club and stayed throughout the summer transfer window. Jansen eventually returned to training from injury ahead of the new season and made his return in the opening match of the season against Borussia Dortmund, setting up a goal for Robert Tesche in a 3–1 loss. After returning to the first team from injury, Jansen began playing in the midfield position, either at left-wing or left-midfield for most of the season. On 5 November 2011, he scored his first goal of the season in a 2–2 draw against Bayer Leverkusen. Despite suffering from injuries during the season, Jansen went on to make 31 appearances and scored 5 times in all competitions.