bundesliga.com has everything you need to know as Roger Schmidt's side look to get their campaign up and running...
After a disappointing Matchday 1, where Bayer were made to rue their missed chances in a 1-0 defeat away to AS Monaco, it is imperative Schmidt's side get some points on the board against Benfica. A win would kick-start their European campaign, but a defeat would leave them with a mountain to climb in Group C.
Sebastian Boenisch, who missed Saturday's match against SC Freiburg, continues to struggle with a damaged heel. Gonzalo Castro also has a niggle that will keep him out, so expect Wendell and Stefan Reinartz to deputise. Emir Spahic (pictured) is currently serving a Bundesliga ban, but should feature.
Goalkeeper Julio Cesar, who was rested for the weekend's league game against GD Estoril Praia, will return in place of the suspended Artur Moraes. Other than that, no other changes are expected, with Anderson Talisca and Andreas Samaris set to benefit from being taken off with 30 minutes to spare on Saturday evening.
Lars Bender (pictured right) gave a captain's performance at the weekend, dropping into the back line as his side gained a point against SC Freiburg despite playing the majority of the game with ten men. It goes without saying, Leverkusen will need the Germany international to put in an equally impressive defensive display against the Reds.
Young Brazilian attacking midfielder Talisca has been a revelation for the Lisbon side since joining in the summer from Bahia. He has already found the net five times in six appearances in a withdrawn role behind the striker, with his form crucial to whether Benfica will be able to get anything from this game.
Roger Schmidt (Leverkusen head coach): "We showed [in Monaco] we know how to play in Europe. But it's not just about playing well, it's about winning."
Jorge Jesus (Benfica head coach): "Both sides lost last time out, so a win tomorrow is critical to both."
Leverkusen recorded a 0-0 draw at Freiburg on Saturday, with that point coming off the back of a 1-0 win over FC Augsburg - their only win in the last five games. Benfica are unbeaten in the league and sit top, enjoying 3-2 and 3-1 wins against Estoril and Moreirense FC in their last two outings respectively.
The two sides last met in the 2012/2013 UEFA Europa League round of 16. Bayer went down to a 1-0 defeat in the home leg before losing the second leg 2-1 to go out 3-1 on aggregate. Their only previous meetings came in the UEFA Cup Winners Cup in 1994, where Benfica went through on away goals after a breathtaking 4-4 draw.
Leverkusen: Leno - Hilbert, Toprak, Spahic, Wendell - Reinartz, L. Bender - Bellarabi, Calhanoglu, Son - Kießling
Benfica: Julio Cesar - Maxi Pereira, Luisao, Jardel, Eliseu - Samaris - Salvio, Perez, Gaitan - Talisca - Lima