In 1998, Weidenfeller transferred to the 1. FC Kaiserslautern youth team and later was used in the second team. For the 2000/01 Bundesliga season he was promoted to the first team but made only six league appearances in two years.
Borussia Dortmund
Weidenfeller moved to Borussia Dortmund in 2002 on a free transfer as a possible replacement for Jens Lehmann, who had moved to Arsenal in 2003. Weidenfeller had reportedly been unhappy at Kaiserslautern, where he was used mainly as a backup to Georg Koch. His debut for Dortmund came on 17 December 2003 against his former club, Kaiserslautern, in a 1–0 loss. In 2005, Weidenfeller underwent surgery following a meniscus tear in his left knee during training. Early in the 2007–08 season, Weidenfeller was given a three match ban and fined €10,000 for racist insults leveled against Schalke 04 striker Gerald Asamoah. Asamoah originally reported Weidenfeller after a match on 18 August 2007 between the two clubs, where the incident occurred after a clash between the two in the 51st minute. Weidenfeller offered an apology to Asamoah following the news reports but denied making the statement. Weidenfeller won the Bundesliga with Dortmund in 2011 and went on to win the Bundesliga and DFB-Pokal double with the club in 2012. In the DFB-Pokal final, he was substituted in the 33rd minute due to a collision with Mario Gómez. On 6 May 2013, Weidenfeller signed a contract extension with Borussia Dortmund, keeping him at the club until 2016. On 27 July 2013, Weidenfeller won the 2013 DFL-Supercup with Dortmund 4–2 against rivals Bayern Munich. However, with manager Jürgen Klopp leaving at the end of the 2014/15 season, the replacement manager Thomas Tuchel chose new signing Roman Bürki as his first choice goalkeeper as Dortmund began the season in excellent form, winning their first eleven games under Tuchel. Weidenfeller would continue to play in the club's European matches. On 5 February 2016, Weidenfeller signed a new one-year deal with Borussia, keeping him at the club until 2017. On 9 May 2017, he extended his contract until 2018. At the end of the season 2017–18, he finished after his substitution for goalkeeper Bürki on 34 Matchday his active career, but will continue to work in another capacity at Dortmund. His farewell match took place on September 7, 2018 in the Signal Iduna Park where Roman & Friends won against the BVB All Stars and Weidenfeller scored two goals. Following Weidenfeller's retirement, he remained at Borussia Dortmund as an international ambassador.
International career
In November 2013, Weidenfeller was called up to the German national squad for his first time for the friendlies against Italy and England. He received his first cap when he started against England at the Wembley Stadium on 19 November 2013, making him the oldest ever German goalkeeper débutant. He then appeared for the game against Cameroon, where the game ended tied at 2–2. He made his third appearance on the next game against Armenia where Germany won 6–1. Both games were international friendlies. He was nominated as a reserve keeper behind Manuel Neuer for the 2014 FIFA World Cup in Brazil, where the German team won the title a fourth time, but Weidenfeller wasn't used in any match. Weidenfeller made his first appearance for the German national team in a competitive match against Gibraltar during the UEFA Euro 2016 qualifying in June 2015. His international farewell came with this match after winning five caps in total.
