user: Question: WHAT IS THE APPOINTMENT DATE WITH A Pre-season POSITION, AND REPLACED BY Thomas Thomasberg?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment', 'Position in table']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['AaB', 'Erik Hamrén', 'End of contract', '30 June 2008', 'Bruce Rioch', '1 July 2008', 'Pre-season']
SQL:

assistant: SELECT "Date of appointment" FROM "Table" WHERE "Position in table" = 'Pre-season' AND "Replaced by" = 'Thomas Thomasberg';