CREATE TABLE table_45346 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Location" TEXT, "Final Score" TEXT, "Attendance" TEXT, "Record" TEXT)

Who did the argonauts play against during the game that had 19,423 fans in attendance?
SELECT "Opponent" FROM table_45346 WHERE "Attendance" = '19,423'
SELECT "Opponent" FROM "table_45346" WHERE "Attendance" = '19,423'