Arsenal's preparations for Sunday's home clash with Tottenham Hotspur have been hit by uncertainty over centre-back Gabriel, whose thigh injury is expected to rule him out of the showdown.
Gabriel has been a cornerstone of Mikel Arteta's defence this season but limped off during Brazil's friendly against Senegal last week, and his absence would leave the Premier League leaders without their most dominant aerial presence.
Arsenal return from the international break four points clear of second-placed Manchester City but Arteta's side stumbled last time out in a 2-2 draw at Sunderland.
They have conceded just five league goals all season but Gabriel's injury - amid media reports that he could be out until January — plus doubts over the fitness of Martin Odegaard and Gabriel Martinelli among others - could test Arsenal's strength-in-depth in a fixture that is always fiercely competitive.
"Gabriel is a top defender and I don't care who comes in, it will be tough to take. Arsenal have good players but there aren't many Gabriels around," former England forward Alan Shearer told Betfair.com.
"Defensively he's rock solid and has played a huge part in what Arsenal are doing, but certainly from set-pieces, he's a huge cog in what they do in terms of scoring goals and making it very difficult for defences as well.
"Although Arsenal have a good replacement to come in and replace him, they're losing probably the best centre-half in the Premier League."
Arsenal could replace Gabriel with Ecuador international Piero Hincapie or Spaniard Cristhian Mosquera, while Riccardo Calafiori, if fit, could switch from left back to centre back.
Tottenham have been buoyed by a much-improved defence under new manager Thomas Frank and have the best away record in the league. Spurs sit fifth and have shown they can trouble anyone on the road, having won at Manchester City earlier this season.
However, long-term injuries to James Maddison, Dejan Kulusevski and Dominic Solanke have blunted their attacking edge, leaving winger Mohammed Kudus, who should himself be back from injury, to shoulder the creative load this season.
Arsenal have dominated recent derbies, unbeaten in the last six meetings, but unpredictable Spurs' pressing game makes them dangerous opponents. A win for the visitors would tighten the title race and inject fresh intrigue into the top-four battle.
Liverpool's post-title hangover
Manchester City head to Newcastle United for Saturday's late kickoff where Erling Haaland's firepower will be on show. The Norway striker has been in devastating form, spearheading a City side that looks every inch a title contender.
Pep Guardiola's men return from the international break riding a four-game winning run in all competitions, including a 3-0 statement victory over Liverpool that marked the Spaniard's 1,000th game in management.
With Arsenal's recent slip leading to a narrowing of the gap at the top, City will be eager to maintain momentum with Haaland showing no signs of slowing down, having bagged 32 goals in 20 games for club and country this season.
Newcastle, meanwhile, remain a puzzle.
Eddie Howe's team have oscillated between excellence -- seen in League Cup and Champions League wins -- and Premier League defeats that have left them 14th, two points above the drop zone. Which version of the Magpies turn up could define the contest.
Liverpool will look to shake off their post-title hangover against struggling visitors Nottingham Forest on Saturday.
Arne Slot's champions have plummeted to eighth after five defeats in six league games, with their humbling at Manchester City before the break capping a miserable run.
There were flickers of revival with wins over Aston Villa and Real Madrid, but consistency remains elusive.
Forest arrive buoyed by a 3-1 win over Leeds United and a gritty draw with Manchester United under Sean Dyche, though they still sit second-bottom and are winless away from home.
Liverpool are eight points adrift of Arsenal and cannot afford another slip. With goalkeeper Alisson close to returning and Anfield's roar behind them, the Reds will expect to win.
Manchester United host Everton on Monday looking to extend a five-game unbeaten run under Ruben Amorim. They have climbed within a point of the top four, with Bryan Mbeumo's scoring streak a key factor in their recent resurgence.
