The one whose name is not known should not be called out to by ‘Mohammed’…
Changing your name upon embracing Islaam
Is the new Muslim required to change his name?
Asking to be called by the name of a disbeliever
[There are] some people called Muhammad or ‘Abdul-’Azeez [for example who] ask to be called by the name of a non-Muslim [football] player; so is this permissible, and would this be [considered as] resembling [the disbelievers]?
Changing name upon embracing Islaam
Is it permissible for a person who has embraced Islaam to change his name?