Whether it's the socks pulled down around the calves, the tiniest of shin pads, the throwback nature of the way in which he plays the game or his predilection for an all-night party to celebrate any number of titles, the 29-year-old is the archetypal lovable rogue.
Back in 2021, his star was very evidently on the rise, and a £100m switch to Man City from boyhood club Aston Villa was not only the highest transfer fee ever paid by a British club at the time, but it was also the most expensive fee ever paid for an English player.
Pressure was always going to be put on Grealish's shoulders as a result, and that much was evident in his output during that first season at the Etihad Stadium.
Three goals and three assists in 26 English top-flight games didn't compare too favourably to his final season with Villa (20/21), when he scored six goals and provided 10 assists - also in 26 matches.
We should bear in mind the leap that the attacking midfielder cum left-winger will have had to make given that Villa, with respect, weren't the team then that they are now. Grealish wasn't exactly carrying them, but he was a swashbuckling captain who led from the front and it was always going to be a big step up joining the reigning Premier League champions.
A third of his total shots from the 21/22 season - 22 from 66 - were on target, and as if to give that particular metric some symmetry, 22 were off target and 22 were blocked. One in three shots testing the opposing keeper certainly wasn't to be sniffed at, whilst four of his six big chances were converted in that campaign too.
93 chances created and a season-high pass accuracy of 91 per cent thanks to 1432 successful passes from 1636 will undoubtedly have pleased Pep Guardiola, a manager whose professional demands have remained consistent and legendary throughout his career on the touchline.
At the end of the 22/23 season, Man City memorably completed the treble; undoubtedly the zenith of Grealish's career.
In the Champions League particularly, he was one player who wasn't frightened to take on his opponent (3.8 dribbles per 90 minutes) and get into the area. Where he was perhaps found wanting was in his ability to find the net as one goal from the 63 shots taken would show.
The below graphic also shows a lack of defensive actions for the then 26-year-old, and a low percentage of possession won back.
Might questions already have been asked about Grealish's continued suitability for the team as far back as when the club were celebrating the biggest moment in their history, given a poor all-round contribution?
Fast forward to this season and the notion that Grealish might be surplus to requirements is still a discussion point.
Pep Guardiola would appear to prefer Savinho or Jeremy Doku as starters in the wide areas, and it's easy to see why.
Sticking with the Champions League firstly, though Grealish has still managed to get touches in the opposition box (5.1 per 90 mins) and a reasonable though not excellent 1.8 shots per game, he's attempted nowhere near the dribbles of seasons past - just one per 90 minutes.
His defensive actions have gone down from 3.5 per 90 to 2.5, and possession won has dipped significantly, from 4.7 per 90 to 2.3.
Doku won't impress Guardiola with his lack of defensive work rate either, but 16.9 touches per 90 in the opposition box, 10.8 dribbles attempted and 3.3 chances created speaks for itself.
In the Premier League this season too, Grealish has continued to struggle, scoring just one goal in his 16 appearances, of which only two were for the full 90 minutes.
A recent 6-0 win over Ipswich in which the England international played for 27 minutes saw Grealish touch the ball on 22 separate occasions, but tellingly just one of them was in the box against a very accomodating opponent.
Guardiola attempted to motivate Grealish recently by starting Savinho in the game against West Ham whilst urging the England man to get back to his best.
"Savinho is in better shape and everything than Jack, and that's why I played Savinho," Guardiola told reporters. "Do I want the Jack that won the treble? Yeah, I want it, but I try to be honest with myself for that. They have to fight... every single day, every single week and every single month."
Having reached the pinnacle of club football with the treble win and with age now catching up with him, there are reasons to believe that, maybe, Grealish just doesn't have it in him to scale the mountains and conquer the peaks that Guardiola wants him to.
It must be incredibly frustrating too when the likes of Savinho are posting figures such as a 91.7 per cent pass accuracy, 23 shots on target from 47 taken and 29 tackles made, the latter metric also being an interesting one to occupy his manager's time because it shows a desire to get his hands dirty in the game. Something that's all but disappeared from Grealish's work.
Of course, with the outcome of the 115 charges being levied against the serial Premier League winners due quite soon if reports are accurate, there's a possibility that whatever he says in public, Pep Guardiola might not even be at City in 25/26 if the decision goes against the club and the punishment metered out is severe.
Furthermore, there's the question of Grealish's contract and whether it should be renewed. The current one runs out in June 2027 and it's already becoming difficult for the player to justify his £300,000 per week salary (Capology).
Only Erling Haaland, Kevin De Bruyne and Bernardo Silva earn more at City and all three have certainly provided more value than Grealish who is also the sixth-highest earner in the entire Premier League.
Doku and Savinho earn £50,000 per week and £40,000 per week respectively by way of comparison, so as we can see, things are not looking good for the Birmingham-born man for any number of reasons.
Unless there's a decent upturn in all aspects of his game over the next few months there's a strong likelihood he'll be put up for sale in the summer. If he continues to disappoint, however, City might have to write this one off; when you consider the potential transfer fee plus wages, and an evident lack of value at present, there won't be too many takers.
