Due to travel restrictions around the continent, enforced by COVID-19, neither of these teams will be able to play their respective home ties at their home stadiums.
The second leg next week will take place at the Karaiskakis Stadium in Greece - the home of Olympiacos.
Benfica reached the round of 32 by finishing second in a group that included Rangers, Standard Liege, and Lech Poznan. They only finished second due to an inferior head-to-head record against Rangers based on away goals.
They had drawn 3-3 against the Scottish team at the Estadio da Luz before a 2-2 draw at Ibrox.
Overall though, it has not been a great season for Benfica so far. They currently find themselves fourth in the Primeira Liga, behind Sporting Lisbon, Porto and Braga.
With 19 games played in the season, Benfica are 13 points behind leaders Sporting. However, they are still well in the hunt to finish second, with Jorge Jesus's side currently just three points behind Porto.
Arsenal, on the other hand, are 10th in the Premier League. Their revival around the Christmas period hit a dead end with losses to Wolves and Aston Villa.
However, they recovered well to beat Leeds United 4-2 last weekend. Pierre-Emerick Aubameyang scored a hat-trick as the Gunners were rampant in disposing of Marcelo Bielsa's side.
Benfica vs Arsenal Head-to-Head
In three previous games between these two sides, Arsenal have won two, while Benfica have won one.
Benfica form guide: D-W-W-D-L
Arsenal form guide: W-L-L-D-W
Benfica vs Arsenal Team News
The Portuguese giants have both Andre Almeida and Gilberto ruled out with injuries, which leaves them in a tight spot at right-back. Diogo Goncalves is likely to play in that position on Thursday night.
Injured: Andre Almeida, Gilberto
The Europa League represents Arsenal's best chance to win a trophy this season. With that in mind, it is likely that Arteta will field a strong enough lineup to get a positive result against Benfica in this first leg.
However, Thomas Partey and Kieran Tierney are both unlikely to be fit enough to feature in this game.
Injured: Thomas Partey, Kieran Tierney
Benfica vs Arsenal Predicted XIs
Benfica Predicted XI (4-4-2): Odysseas Vlachodimos; Diogo Goncalves, Nicolas Otamendi, Jan Vertonghen, Alex Grimaldo; Rafa Silva, Adel Taarabt, Julian Weigl, Pizzi; Darwin Nunez, Haris Seferovic
Arsenal Predicted XI (4-2-3-1): Bernd Leno; Hector Bellerin, David Luiz, Gabriel Magalhaes, Cedric Soares; Granit Xhaka, Dani Ceballos; Bukayo Saka, Emile Smith Rowe, Nicolas Pepe; Pierre-Emerick Aubameyang
Benfica vs Arsenal Prediction
Due to Arsenal's inconsistency this season, Benfica will believe that they have a chance to take a big scalp in this game.
However, the Portuguese side are not in the best of form and have had some issues at both ends of the pitch throughout the season.
We expect Arsenal to secure a win in this first leg.
Prediction: Benfica 1-2 Arsenal