Poznan, meanwhile, who sit five points behind Benfica in Group D, must win if they are to have any chance of qualifying for the knockout stages.
Benfica returned to winning ways in the Primeira Liga on Monday as they beat Maritimo 2-1 away from home.
Jorge Jesus is still aware of his side's defensive frailties however, with Benfica conceding 10 goals in the Portuguese top flight as well as seven goals in the Europa League this campaign.
Benfica head into Thursday's match knowing that a victory would secure their qualification to the knockout stages.
The Eagles have never lost in five previous meetings with Polish opponents, winning the reverse fixture against Lech Poznan 4-2 in October.
Benfica are also unbeaten in their last eight group stage games in the Europa League – winning six and drawing the other two – scoring two or more goals in each match in this run.
Lech Poznan still have a slim chance of progressing from Group D, despite losing 2-1 to Standard Liege in their last Europa League match.
The Polish outfit come into the game off the back of a narrow 1-0 away victory at Lechia Gdansk, which was their first win in four matches in all competitions.
After winning their first ever meeting with Portuguese opponents back in February 2011 – a 1-0 victory over Braga – Dariusz Zuraw's side are winless in their last four such games, failing to score on three of those occasions.
Lech Poznan, who have also lost four of their last five Europa League group stage games, know that they must win in Lisbon if they wish to progress to the last 32.
Benfica Europa League form: WWDD
Benfica form (all competitions): LDLWDW
Lech Poznan Europa League form: LLWL
Lech Poznan form (all competitions): WWLDLW
Poznan defender Dorde Crnomarkovic is suspended after being shown a red card in the loss to Liege.
Benfica possible starting lineup:
Vlachodimos; Goncalves, Otamendi, Vertonghen, Grimaldo; Rafa, Pires, Pizzi; Everton, Seferovic, Waldschmidt
Lech Poznan possible starting lineup:
Bednarek; Czerwinski, Satka, Rogne, Puchacz; Skoras, Tiba, Moder, Marchwinski; Ramirez; Ishak
We say: Benfica 2-1 Lech Poznan
With Benfica conceding 12 goals in their last six matches in all competitions, Lech Poznan will believe they can cause problems offensively, however the home side should have enough quality to secure the three points in Group D.