Leverkusen sit third in the early Bundesliga table, and made a superb start to life under Roger Schmidt in scoring 22 goals in their first six competitive fixtures of the season in all competitions.
Their goals have dried up somewhat in recent weeks, however, and Schmidt's side lost 1-0 at Monaco in their Group C opener a fortnight ago - Joao Moutinho striking for the French side after Leverkusen had missed a host of chances.
Leverkusen were also kept at bay by Freiburg in a 0-0 draw last Saturday, but displayed impressive resilience to take a point from a fiery clash in which defender Emir Spahic saw red after just 28 minutes.
Schmidt believes that Leverkusen's performance at the Mage Solar Stadion shows that they have the endurance to cope with the rigours of continental competition.
"It's a good sign that the team is in good shape physically," Schmidt said.
"The energy levels are full and that's good to know ahead of such an important game."
Yet they have good reason to be confident of bouncing back versus Jorge Jesus' team, who have been superb in the Primeira Liga but displayed worrying signs of fallibility in their group opener with Zenit.
Respective opening-round defeats have left Leverkusen and Benfica in need of victory to avoid the danger of becoming cut adrift at the bottom of the group, but both head into Wednesday's contest at the BayArena with absentees in key areas.
