It has come to the point where Chelsea needs to look at the opponents sneaking up behind them. Not just for top four security, but for the security of Thomas Tuchel.
Since the Roman Abramovich takeover, there has not been a single manager that has survived, having finished outside of the top four Premier League spots. When it starts to look like top four is out of the question, the big boss starts looking ahead to the future, scouting for the next best thing.
It's quite scary to think that Arsenal, Tottenham, and Manchester United could find their way into a top four challenge, pulling Chelsea into the mix with them.