In the space of a minute, Arsenal fans experienced extreme highs and lows in a season which refuses to be simple.
Calum Chambers found the net for the Gunners just 23 seconds after entering the field of play, squeezing the ball over the line to give his team the lead against Leeds United.
However, Chambers was only on the pitch due to the withdrawal of Ben White early in the second half, and Arsenal will be worried about the health of the £50million centre-back as they prepare to return to league action on Saturday.
The Carabao Cup fourth round victory over Leeds was wrapped up 15 minutes later, as Eddie Nketiah rounded Illan Meslier and put the ball into an empty net, but the positive of the result will be tempered by concern about potentially losing one of this season's great constants.
Image:AFP via Getty Images)
Mikel Arteta appeared to confirm after the game that White's issue was illness rather than injury.
"With Ben, and with some others - we lost Pablo [Mari] today, he was going to start and he couldn't start because he had a bug - I think there is something happening around here," the manager said.
"He wasn't feeling great in the second half and we decided to take him off."
However, even one game without the Gunners' ever-improving centre-back partnership could feel like one too many.
Arsenal's 2021-22 season can be divided into two periods: the three games before Ben White and Gabriel partnered up in the Premier League, and the six games after.
Those first three games saw the Gunners beaten three times, with White enduring a tough time against Brentford on his debut before sitting out the defeats to Chelsea and Manchester City after a positive Covid test.
When the England international returned to the fold, so did his Brazilian colleague, and Arsenal have yet to lose a game which the pair have started together at centre-back.
While the quality of Arsenal's starting centre-backs is plain to see, there's still something impressive about the speed with which they have been able to form a cohesive partnership.
Arteta has instructed the defenders well, by the sounds of it, with Gabriel explaining how the manager has made their task clear.
"He wants us to know the moments to attack and the moments to defend. That's what we are trying to do, and we know now when to drop deep and when to push up," the Brazilian said ahead of the goalless draw with Brighton at the start of October.
"Having good timing on the pitch is essential and he talks to us about that a lot. He also tells us how every game is different here because we're up against players with different attributes."
In the six games with White and Gabriel together in central defence, Arsenal have conceded just six goals.
Two of those were consolations, with Tottenham and Aston Villa both netting when facing three-goal deficits, while the other two were scored by Crystal Palace in a draw at the Emirates Stadium.
If White misses out on Saturday, and a bug which can sideline Pablo Mari may be enough to keep him out as well, a big test for Arsenal could be even bigger.
The Gunners will be up against a Leicester team who boast players with a variety of attributes in their starting XI and on the bench, with a choice between Jamie Vardy, Kelechi Iheanacho and Patson Daka in attack and an impressive supporting cast.
The Foxes go into the game in impressive attacking form, having hit 10 goals across victories over Manchester United, Spartak Moscow and Brentford in their last three games.
Chambers and Rob Holding are the two most likely to fill in for White if required, with neither having featured in the 3-1 victory at the King Power Stadium last season.
It will be a real test even if Arteta's preferred partnership is available, but a requirement to switch things up at the back would only increase that pressure.Read More Read More