Is Jack the lad? Or is Grealish a luxury player that defending Premier League champions Manchester City did not need?
That is a question that has been vexing pundits and fans alike but not one that boss Pep Guardiola or former teammate Micah Richards have any time for.
Grealish is not the first player to struggle to adapt the demands of a complete change of tactical approach, where training and expectations both reside at the very top of the intensity graph and every touch and movement is scrutinised to an almost unhealthy degree.
Since his high-profile £100 million move to City, the affable England international has had to come to terms with being just one of a posse of bejewelled attacking and midfield stars all perfectly capable of being top of the bill if asked to but also more than happy to be completely unselfish and part of a supporting cast.
It takes all new recruits time to acclimatise to Guardiola’s philosophy and demands and Grealish will undoubtedly flourish – as he has in recent games – in the same way as Bernardo Silva, Riyad Mahrez, Ilkay Gundogan, Kevin De Bruyne, Raheem Sterling and Phil Foden have done.
Those teammates have all also been in and out of the side but have collected three Premier League titles in the past four years and are on course for a fourth in five.
Grealish’s gilded new colleagues have also had years to learn and hone the skills that allow them to anticipate – or more likely know – where the next pass is going and instinctively realise where the off-the-ball movements are being made. They are almost programmed in ‘Pep Ball’.
It’s only natural that any new player will take time to get on the same wavelength and there was ample evidence that Grealish is getting there in the recent FA Cup win at Peterborough when he dragged a long, arced, sumptuous Foden pass out of the Cambridgeshire sky and deposited it in the net to seal victory and then again in the 4-1 demolition of neighbours Manchester United.
When City broke their transfer fee record for the 26-year-old last summer, the City chief knew exactly the quality that the club was purchasing and he knew, too, not to expect instant fireworks from the mercurial midfielder who, even without an injury, would need time to settle into new surroundings and learn a playing system alien to him.
Grealish’s close pal Micah Richards, who spent more than three years sharing a dressing room and pitch with his fellow England international, is sure City have a treasure on their hands and is positive his mate made the right move and the right time.
“That £100m price tag was always going to bring pressure no matter what Jack did,” said Richards. “But he is one of the most exciting players this country has produced for years and people are starting to see him settle now at City. His performance in the win over United might not have grabbed the headlines but was superb.
“When you are the big fish at a club it's a lot different. He was THE man at Villa. The dressing room was looking up to him. In some ways he dictated how things were done. At City there are many bigger fish and he has to adapt.
“He’s got world-class talent all around him and a manager who is one of the best there has ever been. The job comes with completely different expectations and requirements.
“Flair players often take more time to settle. There is so much more to come from Jack. He embodies the art of football. He makes the difficult look effortless. I know him well and I know he can deal with the pressure. His ability and mindset are unbelievable.”
Manchester derby ratings
Guardiola, too, has been quick to praise Grealish though not averse to leaving him out – as he does with all his star names from time to time – when the opposition demands a different approach or a training ground performance has dipped a shade.
Grealish was bought for his ball-carrying and retention skills. He is a magnet for defenders and for creating the spaces that other skilled operators in Guardiola’s phalanx of attack-minded players can exploit to the full.
He has, though, had to take on board what Pep has demanded in transition and the omnipresent press that is such an important part of City’s winning game plan.
Grealish has played out wide, not his natural territory growing up at Villa Park, occupied a false nine position that is not practised in many places outside the Etihad Stadium postcode, and at times operated as a playmaking number eight or his favourite number ten.
At some point he may well be asked to operate from deep and he has to learn all the roles and be prepared to be the understudy or be ‘in the wings’ when required.
That means not expecting to score or provide a goal in every game but maybe to be the decoy or the man who assists the assistant.
Guardiola will be the sole arbiter of how good Grealish’s contribution has been – not internet forums, podcasts or social media platforms.
“Players today play for the statistics but this is the biggest mistake,” cautioned the City manager recently without mentioning Grealish by name but clearly having him in mind.
“Statistics are information but it is the players that make the team play good. All anyone has to do is perform to their maximum, help the offensive and defensive process be better. It’s enough.
“Maybe Jack listens too much to what people say. We didn’t buy him to score 45 goals per season. He has other qualities. In the derby in terms of decision-making and using the players in space, he was exceptional.”