Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_2897457_7 ( nationality VARCHAR, player VARCHAR )

### Question ###
How many nationalities does Alex Nikolic come from?

### Accurate SQL ###

SELECT COUNT(nationality) FROM table_2897457_7 WHERE player = "Alex Nikolic"