user: Question: Who did the Jets play in their pre-week 9 game at the Robert F. Kennedy Memorial Stadium?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Game site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '1987-09-13', 'at Buffalo Bills', 'W 31–28', 'Rich Stadium', '76,718']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Week" < 9.0 AND "Game site" = 'Robert F. Kennedy Memorial Stadium';