Sebastien Haller: Dortmund rally behind striker after discovery of testicular tumour

Sebastien Haller scored 21 league goals as Ajax won the 2021/22 Dutch Eredivisie before his summer move to Borussia Dortmund. EPA

Borussia Dortmund striker Sebastien Haller left the team's pre-season training camp in Switzerland on Monday after a tumour was found in his testicle.

The Ivory Coast international joined the German club earlier this month as a replacement for Erling Haaland, who has signed for Manchester City.

"In the course of intensive medical examinations, a tumour was finally discovered in the testicles during the course of the day," Dortmund said.

"During the coming days, further examinations will take place in a specialised medical centre," they added.

Dortmund paid Ajax €31 million ($31.5 million) for the 28-year-old after he scored 47 goals in 66 appearances for the Dutch side after joining in 2021 from West Ham United.

His 21 league goals in 31 games saw him finish as top scorer in the 2021/22 Eredivisie as Ajax secured a record-extending 36th title.

Haller also etched his name into Champions League history, scoring in all six group games - Cristiano Ronaldo is the other player to have achieved that feat - and became the fastest player to record 10 goals in the competition.

"This news today came as a shock to Sebastien Haller and to all of us. The entire Borussia Dortmund family wishes Sebastien a full recovery as soon as possible and that we can hug him again soon," Dortmund's sporting director Sebastian Kehl said in a club statement.

"We will do everything in our power to ensure that he receives the best possible treatment," he added.

Dortmund's first game of the new Bundesliga season is against Bayer Leverkusen on August 6, eight days after heading to third-tier 1860 Munich in the first round of the German Cup.

100 notable summer transfers

Perr Schuurs - Ajax to Torino (£8m). AFP

Paco Alcacer - Villarreal to Sharjah (loan). Getty Images

Matheus Nunes - Sporting to Wolves (£38m). AFP

Tanguy Nianzou - Bayern Munich to Sevilla (£16.9m). AFP

Alan Virginius - Sochaux to Lille (£3.8m). AFP

Thilo Kehrer - PSG to West Ham (£10.1m). Getty Images

Pervis Estupinan - Villarreal to Brighton (£15.1m). Getty Images

Destiny Udogie - Udinese to Tottenham (£15.1m). Loaned back to Udinese. Reuters

Sergio Gomez - Anderlecht to Manchester City (£11m). Photo: Manchester City

Alex Collado - Barcelona to Elche (loan). AFP

Remo Freuler - Atalanta to Nottingham Forest (£9m). AP

Marc Bartra - Real Betis to Tranbzonspor (undisclosed fee). Getty Images

Giovani Lo Celso - Tottenham to Villarreal (loan). Getty Images

Cheikhou Kouyate - Crystal Palace to Nottingham Forest (free). Getty Images

Emmanuel Dennis - Watford to Nottingham Forest (£20m). Getty Images

Nico González - Barcelona to Valencia (loan). AP Photo

Luca Pellegrini - Juventus to Eintracht Frankfurt (loan). AFP

Daniel Wass - Atletico Madrid to Brondby (£1.7m). EPA

Pablo Marí - Arsenal to Monza (loan). AP

Dries Mertens - Napoli to Galatasaray (free). AFP

Jordan Veretout - Roma to Marseille (£9.3m). Reuters

Christian Benteke - Crystal Palace to DC United (undisclosed fee). AFP

Maxwell Cornet - West Ham United to Burnley (£17.5m). PA

Georginio Wijnaldum - PSG to Roma (loan). AFP

Lucas Torreira - Arsenal to Galatasaray (£5m). AFP

Marc Cucurella - Brighton to Chelsea (£55m). Getty Images

Ademola Lookman - RB Leipzig to Atalanta (£12.6m). PA via AP

Renato Sanches - Lille to Paris Saint-Germain (£12.6m). AFP

Riqui Puig - Barcelona to LA Galaxy (free). AP Photo

Alex Telles - Manchester United to Sevilla (loan). AFP

Carney Chukwuemeka - Aston Villa to Chelsea (£20m). Reuters

Kasper Schmeichel - Leicester City to Nice (£1m). AFP

Mattia Viti - Empoli to Nice (£10.9m). AFP

Gabriel Slonina - Chicago Fire to Chelsea (£8.3m). Reuters

Bernd Leno - Arsenal to Fulham (£3m). AFP

Charles De Ketelaere - Club Brugge to AC Milan (£26.8m). AFP

Joe Rodon - Tottenham to Stade Rennais (loan). AFP

Borja Mayoral - Real Madrid to Getafe (£8.4m). EPA

Cesc Fabregas - Monaco to Como (free). EPA

Alexis Beka Beaka - Lokomotiv Moscow to Nice (£11.7m). AFP

Marcus Tavernier -Middlesbrough to Bournemouth (£10m). Getty Images

Aaron Ramsey - Juventus to Nice (free). AFP

Orel Mangala - Stuttgart to Nottingham Forest (£12.7m). AFP

David Raum - Hoffenheim to RB Leipzig (£21.8m). Getty Images

Oscar Mingueza - Barcelona to Celta Vigo (£2.5m). Getty Images

Jules Kounde - Sevilla to Barcelona (£45m). AFP

Dwight McNeil - Burnley to Everton (£20m). Getty Images

Arnaud Kalimuendo - PSG to Rennes (£21m). Getty Images

Filip Kostic - Eintracht Frankfurt to Juventus (£14.4m). EPA

Salvatore Sirigu - Genoa to Napoli (free). Reuters

Mikkel Damsgaard - Sampdoria to Brentford (£12.7m). EPA

Malang Sarr - Chelsea to Monaco (loan). AFP

Issa Diop - West Ham United to Fulham (£15m). Getty Images

Alexis Sanchez - Internazionale to Marseille (free). Getty Images

Timo Werner - Chelsea to RB Leipzig (£18m). AP

Amadou Onana - Llle to Everton (£33.8m). AFP

Emirhan Ilkhan - Besiktas to Torino (£3.8m). PA

Gonçalo Guedes - Valencia to Wolves (£27.5m). AP Photo

Conor Coady - Wolves to Everton (loan). Getty Images

Anthony Modeste - Cologne to Borussia Dortmund (£3.8m). EPA

Angeliño - RB Leipzig to Hoffenheim (loan). Getty Images

Marcos Senesi - Feyenoord to Bournemouth (£12.6m). AFP

Isco - Real Madrid to Sevilla (free). EPA

Raheem Sterling - Manchester City to Chelsea (£50m). Getty Images

Lisandro Martinez - Ajax to Manchester United (£46m). Getty Images

Robert Lewandowski - Bayern Munich to Barcelona (£38.3m). AFP

Hugo Ekitike - Reims to Paris Saint-Germain (loan). AFP

Thomas Henry - Venezia to Verona (£3.8m). Getty Images

Takefusa Kubo - Real Madrid to Real Sociedad (£5.2m). Getty Images

Kalidou Koulibaly - Napoli to Chelsea (£33.8m). EPA

Chancel Mbemba - Porto to Marseille (free). EPA

Breel Embolo - Borussa Monchengladbach to Monaco (£10.6m). EPA

Christian Eriksen - Brentford to Manchester United (free). PA

Raphinha - Leeds United to Barcelona (£49m). Getty Images

Federico Bernardeschi - Juventus to Toronto FC (free). Getty Images

Andrea Cambiaso - Genoa to Juventus (£5.9m). Getty Images

Arturo Vidal - Inter Milan to Flamengo (free). Getty Images

Mohamed Bayo - Clermont to Lille (£11.8m). AFP

Francisco Trincao - Barcelona to Sporting (loan). Getty Images

Samu Castillejo - AC Milan to Valencia (undisclosed fee). PA

Lewis Ferguson - Aberdeen to Bologna (£3m). PA

Keane Lewis-Potter - Hull City to Brentford (£16m). PA

Alessio Romagnoli - AC Milan to Lazio (free). Getty Images

Nathan Collins - Burnley to Wolves (£20.5m). PA

Andriy Yarmolenko - West Ham United to Al Ain (free). AP Photo

David Ospina - Napoli to Al Nassr (free). Getty Images

Kristian Thorstvedt - Genk to Sassuolo (£8.4m). Reuters

Andreas Pereira -Manchester United to Fulham ( £10m). Getty Images

Gabriel Jesus - Manchester City to Arsenal (£45m). Getty Images

Steven Bergwijn - Tottenham Hotspur to Ajax (£26.5m). AP Photo

Andreas Christensen - Chelsea to Barcelona (free). AFP

Sébastien Haller - Ajax to Borussia Dortmund (£30.8m). AFP

Flynn Downes - Swansea City to West Ham United (£12m). PA

Junior Messias - Crotone to AC Milan (£3.8m). Reuters

Luis Sinisterra - Feyenoord to Leeds United (£21.3m). AFP

Brais Méndez - Celta Vigo to Real Sociedad (£12.8m). Getty Images

Moussa Niakhaté - Mainz to Nottingham Forest (£8.7m). Getty Images

Romeo Lavia - Manchester City to Southmpton (£12m). AP Photo

Tyler Adams - RB Leipzig to Leeds United (£20m). AP

Axel Witsel - Borussia Dortmund to Atletico Madrid (free). EPA

Maya Yoshida - Sampdoria to Schalke (free). AP Photo

Tyrell Malacia - Feyenoord to Manchester United (£12.9m). AP Photo

Zeki Celik - Lille to Roma (£6m). AFP

Ritsu Doan - PSV Eindhoven to Freiburg (£6.5m). AFP

Divock Origi - Liverpool to AC Milan (free). AFP

Rolando Mandragora - Torino to Fiorentina (£7m). EPA

Joao Palhinha - Sporting to Fulham (£17m). Getty Images

Franck Kessie - AC Milan to Barcelona (free). Getty Images

Trezeguet - Aston Villa to Trabzonspor (£3.4m). AFP

Kalvin Phillips - Leeds United to Manchester City (£45m). Reuters

Giulian Biancone - Troyes to Nottingham Forest (£5m). AFP

Giuliano Simeone - Atletico Madrid to Real Zaragoza (loan). EPA

Raoul Bellanova - Cagliari to Inter Milan (loan). Getty Images

Richarlison - Everton to Tottenham (£50 million). PA

Fabio Carvalho - Fulham to Liverpool (£5 million). PA

James Tarkowski Burnley to Everton (free). Getty Images

Sime Vrsaljko - Atletico Madrid to Olympiakos (free). AP Photo

Dean Henderson - Manchester United to Nottingham Forest (loan). PA

Luuk de Jong - Sevilla to PSV Eindhoven (£3.4m). AP Photo

Henrikh Mkhitaryan - Roma to Inter Milan (free). Reuters

Cenk Tosun - Everton to Besiktas (free). Reuters

Andre Onana - Ajax to Inter Milan (free). Getty

Moussa Sissoko - Watford to Nantes (£2m). AFP

Corentin Tolisso - Bayern Munich to Lyon (free). AFP

Vitinha - Porto to Paris Saint-Germain (£34m). AFP

Romelu Lukaku - Chelsea to Inter Milan (loan). PA

Lorenzo Insigne - Napoli to Toronto FC (free). AP

Sven Botman - Lille to Newcastle United (£31.9m). AFP

Takumi Minamino - Liverpool to Monaco (£15.5m). Getty Images

Alphonse Areola - Paris Saint-Germain to West Ham United (£7.8m). AFP

Lucas Leiva - Lazio to Gremo (free). Getty Images

Joselu - Alaves to Espanyol (free). Getty Images

Matt Turner - New England Revolution to Arsenal (£4.7m). Reuters

Fernandinho - Manchester City to Athletico Paranaense (free). PA

Bartol Franjic - Dinamo Zagreb to Wolfsburg (£6.9m). Getty Images

Wahbi Khazri - Saint-Etienne to Montpellier (free). AFP

Tobias Figueiredo - Hull City to Nottingham Forest (free). PA

Pietro Pellegri - Monaco to Tornio (£3.9m). Getty Images

Erling Haaland - Borussia Dortmund to Manchester City. Getty Images

Malcolm Ebiowei - Derby County to Crystal Palace (undisclosed). PA

Taiwo Awoniyi - Union Berlin to Nottingham Forest (£17m). Getty Images

Gareth Bale - Real Madrid to Los Angeles FC (free). PA

Lucas Alario - Bayer Leverkusen to Eintracht Frankfurt (£5.6m). PA

Sadio Mane - Liverpool to Bayern Munich (£28m). Getty Images

Armindo Sieb - Bayern Munich to Greuther Fürth (undisclosed fee). Getty Images

Nick Pope - Burnley to Newcastle (£10m). PA

Ki-Jana Hoever - Wolves to PSV Eindhoven (loan). PA

Ryan Fredericks - West Ham United to Bournemouth (free). Getty Images

Mario Götze - PSV Eindhoven to Eintracht Frankfurt (£3.4m). Getty Images

Fabio Vieira - Porto to Arsenal (£30m). EPA

Antonio Rudiger - Chelsea to Real Madrid (free). PA

Merih Demiral - Juventus to Atalanta (£17.2m). AFP

Giovanni Simeone - Cagliari to Hellas Verona (£10.3m). AP

Marc Roca - Bayern Munich to Leeds United (£10m). PA

Yves Bissouma - Brighton to Tottenham (£25m). PA

Gavin Bazunu - Manchester City to Southampton (£12m). PA

Darwin Nunez - Benfica to Liverpool (£64.3m). PA

Aurelien Tchouameni - Monaco to Real Madrid (£85.3m). AFP

Nemanja Matic - Manchester United to Roma (free). EPA

Ryan Gravenberch - Ajax to Bayern Munich (£20m). EPA

Giorgio Chiellini - Juventus to Los Angeles FC (released). Getty Images

Cameron Carter-Vickers - Tottenham to Celtic (£6m). AFP

Alexandre Lacazette - Arsenal to Lyon (free transfer). AFP