3Stars average on day 2 of the new season and you'r good to go.
Not sure if it works on best 14 again.. but that's what i do
League is made on day 3.
What i usually do is go into new level with 3Stars Q, on day 1 i buy 3-4 players to fix my team for upcoming Cup games.
Once those cup games are over i sell the players i bought and drop the quality back to 2-3Stars.. This worked fine last few seasons.