user: ### NOW ANSWER:
Question: What week was the opponent the San Diego Chargers?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Kickoff Time', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'September 8, 2002', 'San Diego Chargers', 'L 34–6', 'CBS 1:00pm', '53,705']
SQL:

assistant: SELECT AVG("Week") FROM "Table" WHERE "Opponent" = 'San Diego Chargers';