BERLIN — The mood in Borussia Dortmund’s pre-season training camp in Switzerland couldn’t be more worried.,Only hours after a new arrival, forward Sebastien Haller had been diagnosed a testicular tumour, with the striker leaving for further surgery in Germany, scheduled training sessions took place in a gloomy mood.,In an official statement, the Black and Yellows announced late Monday evening that the 28-year-old first complained of feeling unwell before training Monday morning. “He reported not to feel well and he had symptoms,” head coach Edin Terzic said.,This explains why Haller didn’t attend the teams friendly against the Spanish side of Valencia (3-1) in Altach in Austria near the Swiss border, Terzic added.,The tumour was found during a medical examination in the team hotel, with Haller returning to Germany to undergo further testing.,”This news today came as a shock to Sebastien Haller and everyone else,” the club’s sporting director, Sebastian Kehl, stated.,”The entire BVB family hopes that Sebastien makes a full recovery as soon as possible and that we can give him a hug again soon. We’ll do everything in our power to ensure that he receives the best possible treatment.”,Haller joined Borussia earlier this month from Ajax, with Dortmund paying 31 million euros for a player they targeted to replace Erling Haaland.,The France-born Cote d’Ivoire international scored 34 goals for the Dutch side of Ajax last season, including 11 in eight Champions League games.,Haller in several interviews had spoken about his goal to help his new club return to success.,His former clubs such as West Ham and Ajax said in social media postings that they are shocked and hope for a quick recovery.