![German tennis pro Nicolas Kiefer looks frustrated during his match against Belarusian Mirnyi at the ATP German Masters in Hamburg, Germany, Wednesday, 17 May 2006. Kiefer lost the match in two sets German tennis pro Nicolas Kiefer looks frustrated during his match against Belarusian Mirnyi at the ATP German Masters in Hamburg, Germany, Wednesday, 17 May 2006. Kiefer lost the match in two sets](https://c8.alamy.com/comp/D3NHRG/german-tennis-pro-nicolas-kiefer-looks-frustrated-during-his-match-D3NHRG.jpg)
German tennis pro Nicolas Kiefer looks frustrated during his match against Belarusian Mirnyi at the ATP German Masters in Hamburg, Germany, Wednesday, 17 May 2006. Kiefer lost the match in two sets
![Pro Tennis Player Nicolas Kiefer at the Los Angele Editorial Photo - Image of athletics, returning: 11418946 Pro Tennis Player Nicolas Kiefer at the Los Angele Editorial Photo - Image of athletics, returning: 11418946](https://thumbs.dreamstime.com/b/pro-tennis-player-nicolas-kiefer-los-angele-11418946.jpg)
Pro Tennis Player Nicolas Kiefer at the Los Angele Editorial Photo - Image of athletics, returning: 11418946
![Kiefer criticizes Zverev and Thiem: "Questioning whether they have anything other than tennis balls in their heads · tennisnet.com Kiefer criticizes Zverev and Thiem: "Questioning whether they have anything other than tennis balls in their heads · tennisnet.com](https://www.tennisnet.com/fileadmin/_processed_/d/1/csm_nicolas-kiefer_0ba1ca58f3.jpg)
Kiefer criticizes Zverev and Thiem: "Questioning whether they have anything other than tennis balls in their heads · tennisnet.com
![Nicolas Kiefer - Advantage Tennis Photo site, view and purchase photos of the Tennis player Nicolas Kiefer. Nicolas Kiefer - Advantage Tennis Photo site, view and purchase photos of the Tennis player Nicolas Kiefer.](https://www.advantage-tennis.com/kiefer/IMG_3696.jpg)