why is zverev called sascha

Alexander Zverev is called "Sascha" because it is a common Russian diminutive nickname for the name Alexander. His parents are Russian, and "Sascha" (Саша in Russian) is a traditional affectionate short form of Alexander in Russian- speaking cultures. The nickname combines sounds from the name Alexander, especially from the part "Sander," turning into "Sascha." Although Zverev was born in Germany and identifies as German, the Russian nickname has stuck with him since childhood and is used by close family and fans. He has mentioned that only his close family is allowed to call him "Sascha" professionally, as he prefers to identify with his German nationality in his tennis career.