Arsenal boss Mikel Arteta says their Europa League last-32 second leg with Benfica is like a final for them.
The first leg was drawn 1-1 in Rome's Olympic Stadium, with the second leg - Arsenal's 'home' game - in Olympiakos' Georgios Karaiskakis Stadium in Athens.
"It's a big season and a really important game, mentally and confidence-wise," said Arteta.
"It's going to dictate if we're in another competition for a few more weeks. This is really what we need."
Winning the Europa League is Arsenal's best hope of qualifying for the Champions League. They are 11 points off the top four after a run of one win in six games in all competitions.
"I always feel that it is [pressure], every time you are playing a competition where you can go out and you know the consequences," said Arteta.
"With this club you are always here to win the competition you are in.
"This is the pressure you want. It's much better to have the pressure to win than the pressure not to lose.
"For us tomorrow, it's a final."
Defender Rob Holding will not travel to Greece because of concussion protocols, while midfielder Thomas Partey will have a fitness check after a hamstring injury.
Benfica, who have drawn their past three games, are 15 points off the top in Portugal. Portuguese media reports claim club president Luis Filipe Vieira wants head coach Jorge Jesus to resign.
Match stats
Arsenal have won five of their past six home matches against Portuguese opposition (D1), scoring 20 goals.
Benfica's only previous away match against Arsenal saw them win at Highbury in the European Cup last 16 in 1991-92.
Arsenal have won on each of their previous two visits to Greece, both against Olympiakos, in the Champions League in December 2015 and the Europa League in February 2020.
Since the start of last season, only Nicolas Pepe (10) has had a direct hand in more of Arsenal's 37 goals in the Europa League than Bukayo Saka (three goals, six assists), who netted the equaliser in the first leg.
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