user: Question: Who did the argonauts play against during the game that had 19,423 fans in attendance?
Columns: ['Week', 'Date', 'Opponent', 'Location', 'Final Score', 'Attendance', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'June 27', '@ Blue Bombers', 'Canad Inns Stadium', 'W 23 – 16', '26,155', '1–0']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Attendance" = '19,423';