Not the main line of discussion anyone expected ahead of Arsenal's trip to Old Trafford, eh?
Before the season started, it would probably have centred around what impact Jadon Sancho or Pierre-Emerick Aubameyang could make, but instead the Gunners head north with any chance of success resting on the performance of their 22-year-old summer signing.
Creativity is Arsenal's buzz word for the month, with criticism justifiably aimed at Mikel Arteta for being unable to provide anything noteworthy in an attacking sense despite having plenty of options up front.
Chances are hard to come by and attacking phases often appear laborious and unimaginative, as he works on transitioning his side from a defensive counter-attacking unit into the more familiar 4-3-3 set-up. Efforts have been made to strike that balance, but it's yet to come to fruition.
Why is Gabriel key, then?
Arteta has stated that his centre backs need to take initiative on the ball when his side are in possession and faced with a team sitting deep. This was evident in the loss to Leicester, where Arsenal were a threat throughout the first half aided by David Luiz's dynamic distribution. When the Brazilian came off, Arsenal went limp.
"If you don’t utilise your central defenders you are playing eight [men] against 10 the whole game,” he said. “That’s a really difficult game to play. They [the centre backs] have to step in, they need to know what spaces to attack, which players they need to commit, which players they have to provoke, the areas that we have to provoke as well. They become crucial."
What approach Manchester United take in the game, however, will be answered on Sunday. In the 5-0 hammering of RB Leipzig, Ole Gunnar Solskjaer was rightly praised for the tactics he employed. Starting well in both halves, they came out of the blocks early and congested central areas with the use of a diamond.
Having got their goal, they invited pressure and tore the German side to shreds with some immaculate counter-attacking play. If they're willing to soak up a few waves of attack and transition with pace, Gabriel may be granted time on the ball to forge the foundations of Arsenal moves.
His physicality has been a breath of fresh air to Arsenal's frail defence, but his distribution, too, has been widely praised during his short time in north London. Firstly, having a left footer at centre back helps, but the accuracy of his passing both short and long has helped his side stretch teams, even if what happens after can leave plenty to be desired.
Given Arsenal's paucity up front, set pieces could have a huge say in the visitors achieving anything closely resembling a positive result. This is something that applies in both boxes. Proving himself to be a formidable aerial opponent, the battles with Harry Maguire and Victor Lindelof could have a deciding say in how the end result plays out.
All of the above make him a vital component for Arsenal at Old Trafford, but the most daunting aspect of his task will be carrying the man stood just to his right.
David Luiz, Rob Holding, Pablo Mari and Calum Chambers are all injured, Sokratis isn't even in the squad and William Saliba won't be handed his competitive debut in a game of this magnitude. No, in a bid to banish a 14-year wait for a Premier League victory at United, Arsenal will call upon Shkodran Mustafi.
On paper it should be the World Cup winner taking the new boy under his wing, but Gabriel will be the one carrying his teammate on this occasion. Coming on as a second half substitute in the defeat to Leicester, it was Gabriel who instructed his more experienced co-star to cover the space in front of Jamie Vardy. Of course, he heeded no such calls and let the striker run in to score the winning goal.
Even the most dependable centre backs will falter in their efforts to mark electric duo Mason Greenwood and Marcus Rashford, but while there is faith in Gabriel to step up to the task, the inevitability of Mustafi getting a booking after 40 seconds and hauling one of them down for United's customary penalty offers no such assurances.
Gabriel has his work cut out.
Even the most staunch Arsenal fans will be fearing the worst on Sunday, but if they are to stand any hope of leaving Greater Manchester without their tails between their legs, Gabriel has to have a blinder. There is every chance he'll play well and his side still lose, but not vice versa. Nope.