The Pharaohs will have to do without key injured players including Liverpool’s winger Mohamed Salah, first-choice goalkeeper Mohamed El-Shennawy and talented midfielder Emam Ashour.
Eintracht Frankfurt forwward Omar Marmoush is also doubtful for the game after picking a cold on the eve of the game.
Despite setbacks, the seven-time African champions secured their place in the knockout stage by finishing second in Group B with three points from three consecutive draws.
Meanwhile, DR Congo also claimed the second spot in Group F with three points, thanks to three draws
The Pharaohs boast a commanding track record against DR Congo - winning eight, drawing in three and losing only once - in 12 meetings against the Leapords.
Egypt Portuguese coach Rui Vitoria acknowledged on Saturday that his team is not going into the match at full strength, but he emphasized their determination to fight on the pitch to advance to the quarter-finals.
"We will be facing a strong opponent, but since day one, we have treated every match as a final," stated the Portuguese coach during the pre-match press conference.
Salah, 31, is currently undergoing a rehabilitation program with Premier League giants Liverpool, with hopes of being ready for the AFCON final if Egypt progress.
Meanwhile, veteran goalkeeper El-Shennawy, 35, is confirmed to be sidelined for three months after undergoing laparoscopic shoulder surgery in Germany.
Influential midfielder Ashour, 25, is also doubtful for Sunday's game due to a mild concussion sustained during a training session.
"We are not at 100 percent capacity due to recent problems and injuries. But this is football. We understand our significant responsibility and we will give our best on the pitch," Vitoria said.
Capitalize on Pharaohs' woes
Sebastien Desabre, the Frenchman leading the Leoprads, said he is well aware of Egypt's defensive vulnerabilities in the current tournament and intends to capitalize on them.
"Egypt has conceded six goals and employed three different playing styles. We intend to exploit their defensive weaknesses," Desabre commented on Egypt's struggles at the back.
"We are prepared for the Egypt game, as they possess a formidable frontline," Desabre asserted.
"The group stage is behind us, and this is a do-or-die encounter."
The winner of the Egypt-DR Congo match will face the victor between Equatorial Guinea and Guinea in the quarter-finals.
Check the AFCON matches
Check the AFCON stats
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)