Whether he practices what he preaches, Jose Mourinho has always been a strong advocate of loyalty.
And, whatever his critics may say, the Portuguese boss has always been loyal to Chelsea.
So too have many of his key figures in the dressing room. John Terry is a one-club man and Didier Drogba has joined Mourinho in returning to Stamford Bridge for a second spell.
How, then, would the 51-year-old feel if he woke up to the news that Chelsea legend Frank Lampard is now a Manchester City player?
It hasn't happened just yet, though SkyBet have made the Premier League champions favourites to take the 36-year-old in on loan before New York City FC enter next season's MLS.
One would imagine the 'Special One' would not be too pleased.
Mourinho would undoubtedly acknowledge Lampard's right to go wherever he pleased next and wish him all the best. But, inside - and perhaps even in private - the Blues boss would surely be livid.
For the fact is Lampard could indeed go anywhere - but Man City do not really need him. With the likes of Jack Rodwell and James Milner struggling to break into Manuel Pellegrini's first team, 36-year-old Lampard would be lucky to amass a handful of substitute appearances on current form.
His signing, then, would simply hand Pellegrini an angle with which to play extra mind games with Chelsea and hold against Mourinho. Joining a City-owned MLS franchise is one thing - but turning out for their actual side would be quite another.
Lampard may, of course, be motivated by the fact that the Blues decided not to keep him at the club after 13 years of service, though the farewell was without its bitterness - business is business, c'est la vie.
Even the briefest of spells at the Etihad could change that, though, especially where Mourinho is concerned.
Could Lampard really end up at Manchester City?