Fourteen years is far too long for a manager and it's clear that Mike's run is over...has been for years. I don't care how much money he's due. Cut your loses, pay him off and begin the process of moving forward.
Doesn't matter who the GM is, doesn't matter what the payroll is, doesn't matter who's traded for or what free agents are signed in the off-season; if Scioscia is managing this team next season it'll assuredly be more of the same - only then we'll be looking at 5 straight seasons without a playoff appearance and there'll be no recourse but to fire him at that point anyway. Do it now and get on with it.