Although Villa were able to hold on for a 2-2 draw against Chelsea on Saturday evening, the West Midlands outfit came away from the game with their injury issues.
Goalkeeper Emiliano Martinez, who was already suspended for this game, and Youri Tielemans both picked up injuries, contributing to their absences from the side.
Emery has also decided to drop Pau Torres from his backline, with Robin Olsen, Clement Lenglet and Moussa Diaby the trio of players recalled to the team.
Diaby had been introduced as a substitute against Chelsea before being withdrawn, but Nicolo Zaniolo's recent return to training means that the French playmaker is given another chance.
Meanwhile, Olympiacos head coach Jose Luis Mendilibar has made an array of changes having rested many of his key players at the weekend.
Only Panagiotis Retsos, Chiquinho and Daniel Podence have retained their places in the starting lineup for the game against the Premier League side.
Ayoub El Kaabi gets the nod down the centre of the attack, while goalkeeper Konstantinos Tzolakis comes back between the sticks.
Aston Villa: Olsen; Cash, Konsa, Lenglet, Digne; Bailey, McGinn, Luiz, Rogers; Diaby; Watkins
Subs: Gauci, Wright, Carlos, Torres, Zaniolo, Duran, Iroegbunam, Kesler-Hayden, Munroe, Kellyman, Young
Olympiacos: Tzolakis; Rodinei, Restos, Carmo, Ortega; Iborra, Chiquinho, Hezze; Fortounis, El Kaabi, Podence
Subs: Alexandropoulos, Carvalho, El Arabi, Horta, Jovetic, Papadoudis, Paschalakis, Prekates, Quini, Richards