Most Arabic scholars, although they usually but not always revert to the Spanish name of Esteban, use a different name when they start writing about the man whose fame is growing in North Africa because of his Morocco connection.
Hamza Ben Driss Ottmani, a noted Moroccan writer, wrote the first history of Esteban's story for a North African audience in 2006. His book is available only in French and won the Morocco Book the Year Award. In the book, he writes that research has not yet discovered Esteban's original Arabic name, but Arab writers have settled on "that beautiful family name that his Moroccan admirers affectionally gave him, namely: Mustapha El Azemmouri."
The name and its variants such as Mustafa are very common in the Arab language.