Mesut Ozil did Unai Emery a favour by calling in sick for Arsenal's 3-1 victory against West Ham at the weekend because he gave the new manager, and everybody else at the Emirates, a glimpse into what life without him can look like.
Ozil's absence obviously created headlines. As Arsenal's most high-profile player -- and most highly paid on a reported £300,000 a week -- his failure to make the squad, just six days after going missing during the 3-2 defeat at Chelsea, hinted at Emery's patience with him having already run out.
It soon transpired that Ozil, 29, was unfit to play due to illness. For the seventh time in a year, the former Real Madrid player missed an Arsenal game because he was ill, which must be a concern for the club and an issue that needs to be thoroughly investigated for Ozil's physical well-being, if nothing else.
But if Ozil is going to continue to be so susceptible to illness, Emery will have to start making plans to be without his No.10 because he simply cannot rely on him to be fit to play when needed.
Three Premier League games into his reign as Arsenal manager, however, Emery is already making it pretty clear that he will not indulge Ozil quite so blindly as his predecessor, Arsene Wenger.
Emery wants more from Ozil in every area of the pitch. Wenger was prepared to spare the player from overly onerous defensive duties on the basis that he would deliver in the attacking third -- and Ozil's assists record has always been exceptional at Arsenal -- but the downside of this approach was that it too often left the team one player short when it came to stifling the opposition.
The defining image of Wenger's final months in charge was probably that of Ozil, hands on his hips somewhere near the halfway line, while Arsenal's opponents aimed another shot at goal.
Ozil was afforded too many allowances by Wenger. He was treated like a teenager who was allowed to lie in bed all day while his siblings were expected to clean the house, but Emery has arrived and made it clear that nobody will be given special treatment and everybody is expected to pull their weight.
But there is also the suspicion that the former Sevilla and Paris Saint-Germain coach will not waste too much time attempting to get Ozil onto his wavelength.
He has already sugar-coated his new hard-line approach by handing Ozil the Arsenal captaincy and talking up his qualities, but if those gestures were designed to encourage a positive response, it has so far not been forthcoming.
So Emery can now move forward, safe in the knowledge that he has given Ozil the chance to get on board with his new approach.
Saturday's win against West Ham -- OK, it was only West Ham -- was a sign that Ozil will not be missed, especially if Aaron Ramsey, his replacement, can be persuaded to commit to the club beyond the final year of his contract.
Ozil's supporters will claim that West Ham at home is not the game to judge Arsenal without the former Germany international. They would suggest that his qualities would be more greatly missed against a stronger opponent.
That may be so, but Ozil's weaknesses are also more likely to be exposed by a Manchester City, Liverpool or Chelsea.
Arsenal can beat the weaker teams without him and they will probably be more durable and harder to beat when they line up against their top six rivals with Ozil sat on the bench or in the stands.
Perhaps the realisation has begun to dawn on many at Arsenal that their best-paid player is one who has allowed the modern game to pass him by.
His total lack of defensive work rate has made him a liability against stronger opponents and Emery's Arsenal cannot afford to accommodate him on the basis that he might create a chance for their forwards in the final third.
That Ozil was given such a lucrative contract extension earlier this year -- he is now committed to the club until June 2021 -- was bordering on the reckless by Arsenal considering his contribution to the team.
There was no queue of clubs waiting to sign him on a free transfer this summer, when he would have been out of contract had he not signed his new deal, so why were Arsenal so keen to break the bank to keep him?
Emery is unlikely to have shed a tear had he arrived at Arsenal without Ozil in his squad, but as it stands, it is a problem that he has to deal with.
Still, if Ozil continues as he has started under his new boss, it is a problem that Emery will find very easy to address.