It was a disappointing first leg on Arsenal's behalf, as they did so well to finally break down the barricaded defence. Jack Wilshere found Alexandre Lacazette superbly, who then nodded home past Jan Oblak.
The Gunners were helped with an early sending off, but it didn't tell the tale for the rest of the tie. Arsenal will be hoping they can turn the tie around, but they will need luck on their hands.
The kids did alright
In Arsenal's most recent game, with Manchester United, fans witnessed a new-look side. Because of all the emphasis on the second leg, Arsene Wenger played a second-fiddle eleven, giving some youngsters a chance.
Two starlets in particular stood out to many. Konstantinos Mavropanos and Ainsley Maitland-Niles were two of the best players on the pitch, despite being on the losing side.
It was also a chance for Henrikh Mkhitaryan, a player who always impressed in the Europa League, to make his return from injury. Perhaps the script was written for the Armenian, as he slotted the ball into the far post against his former club.
It's unclear whether Mkhitaryan will start in this game or not, but seems as he was used last time out, it's safe to predict so.
All or nothing
European competition is one which has eluded Arsenal, but this year it's more important than ever to win. The top four is out of Arsenal's grasp, so winning the Europa League is their only hope of returning to the Champions League.
It would arguably be a better way to qualify, given the news of Wenger's departure. Sending the loyal Frenchman out with a European trophy would be quite the tribute.
It's quite a different tale for Atletico Madrid, who sit second in La Liga. They would still like to lift the Europa League, though, given their rivals Real Madrid have booked their place in the Champions League final.
That said, it's important Arsenal give all they've got in Madrid. It is their only hope to consider Wenger's final season a 'successful' one, and it will give the new manager something to look forward to.
Arsenal should feel an attacking side, and go into the game with an all-out attitude. It's vital they secure the away goal, and if they can score without reply, then that would be even better.
There's no disasters for Arsenal, which will come as a breath of relief. They rested a number of their key players in the Premier League match at the weekend.
Mesut Ozil, Jack Wilshere, Aaron Ramsey, Laurent Koscielny and Shkodran Mustafi along with others were rested on Sunday. It will be relatively the same team for Arsenal as it was in the first leg.
That said, Henrikh Mkhitaryan may slot into the starting eleven, as he is an important player for Arsenal. Pierre-Emerick Aubameyang is cup tied in this competition. Mohamed Elneny and Santi Cazorla will miss the game through injury.
Diego Costa, a well-known figure around the Arsenal camp, is nearing full match fitness in time for this tie. He was an unused substitute in the first leg.
Sime Vrsaljko will miss the game due to his early red card in the game at the Emirates.