Egg1

It changes from changed to extended once you get the "Reminder: Contracts about to end" mail at the end of each regular season. Then you have until day 77 to sign them or else be released to FA. If you offer it before that message, it changes the whole contract. My opinion is just wait till the mail since it seems their happiness doesn't affect their play (I had 2 players in red happiness but performed over a point per game)