CREATE TABLE table_24172157_3 (date_of_vacancy VARCHAR, table VARCHAR, team VARCHAR)

What is the date of vacancy for the Liverpool team with a table named pre-season?
SELECT date_of_vacancy FROM table_24172157_3 WHERE table = "Pre-season" AND team = "Liverpool"
SELECT "date_of_vacancy" FROM "table_24172157_3" WHERE "Liverpool" = "team" AND "Pre-season" = "table"