It was the sight no Arsenal fan wanted to see: Aaron Ramsey limping off the pitch in Naples clutching his hamstring, heading back down the tunnel in distress.
This wasn’t how it was supposed to all end. The Juventus-bound midfielder was supposed to bow out with another cup final winner, this time in the Europa League.
Instead, his last appearance as a Gunner may well have come in Thursday night's quarter-final win at the San Paolo.
It all depends on what the specialists say over the next few days.
“I don’t know if we’ll see him again before the end of the season,” Arsenal manager Unai Emery conceded following the 1-0 victory over Napoli.
It was an injury that took the gloss off what was a superb night for the Gunners – who silenced a raucous Neapolitan crowd with an Alexandre Lacazette free-kick to book their spot in the Europa League semi-finals for a second successive year.
Just like last season, they will head to Spain for their last-four assignment, this time to Valencia.
It won't be easy but given Emery’s incredible record in the competition, you wouldn’t bet against him going one stage further than predecessor Arsene Wenger managed in his final season in north London.
But before Arsenal can begin to focus on Valencia, attention must turn once again to the Premier League – and the race for the top four.
Getty Images
The Gunners have their Champions League destiny in their own hands thanks to the win at Watford on Monday night, but they are well aware that there is little room for error with just five games remaining.
With three of those five games away from home, it’s imperative that Emery’s side pick up maximum points in their two remaining fixtures at the Emirates – starting on Sunday, against Crystal Palace.
There will be plenty of changes to the starting XI, something Emery admitted after the win in Naples, with the Spaniard looking to keep his players as fresh as possible for the run-in.
“It’s very important now for the players to have some rotation because some players are injured and we need different players with new energy,” the three-time Europa League winner explained.
"Sunday is going to be very difficult, some of the players who played [in Naples] maybe cannot play on Sunday."
One player who looks certain to come in is Mesut Ozil, who was an unused substitute in Italy.
The German has enjoyed a bit of renaissance over the past few months, working his way back into the first-team picture after finding himself marginalised by the Spaniard around the turn of the year.
Despite not featuring against Napoli, he has been a regular starter in the past six weeks – especially at home – and now is the time when Ozil must really stand up and prove he is worth the £350,000 Arsenal pay him each week.
The 30-year-old deserves credit for the way he has forced his way back into Emery's thinking. His work-rate has certainly improved and he has sparkled at times at the Emirates, particularly during the recent win over Newcastle.
Speaking after that game earlier this month, Emery said: “Mesut is working very well, he is playing well and he is helping us. I am very happy with him.
"Each player is helping us with his quality and with good behaviour. This is the spirit I want so they are doing that, Mesut is also."
Ozil’s return to the side has played a big part in Arsenal’s impressive recent form and with Ramsey now sidelined through injury, Arsenal certainly need their star playmaker more than ever.
As well as Ozil has played during the past couple of months, he has been outshone by the Wales international – whose influence has been huge, both in the Premier League and in Europe.
Ramsey has been the driving force in Arsenal’s midfield and his absence will be felt massively over the coming weeks, as Martin Keown pointed out following the win in Naples.
"Now the dust settles on it, Ramsey, that's a huge loss," the former Arsenal centre-back said on BT Sport. "There's the top four to aim for, there's a Europa League final they need to get to to go one better than they did last year.
"Without Ramsey in the team, it's going to be very tough for them now, and it's about the solution to find someone to play instead of him. Is it going to be Ozil or is [Emery] going to have to change the system?”
Nobody really gave Arsenal a chance of qualifying for the Champions League at the start of the season but, with five games to go, the chance of returning to Europe’s elite competition is within their grasp.
Now is the time for the club’s big players to stand up and seize that opportunity and nobody at Arsenal is bigger than Ozil.
The German is the Gunners' highest-paid player and he needs get his team over the line in a fierce top-four battle which looks certain to go right to the wire.
There are plenty who say the playmaker is a waste of money and that it was a huge mistake for Arsenal to hand him that bank-busting contract in January 2018.
However, he can now go a long way to repaying Arsenal's faith and silence his critics over the coming weeks by filling the leadership void left by Ramsey – starting against Crystal Palace on Sunday.