The match with Empoli kicks off at the Gewiss Stadium in Bergamo at 19.45 UK time (18.45 GMT).
La Dea know even a win might not be enough to guarantee Conference League qualification, because Fiorentina have a superior head-to-head record.
Ilicic has not played since early February, as the mental health issues that had already affected him in 2020 came back to the fore.
Coach Gian Piero Gasperini put the Slovenia international in the squad and during the warm-up he was given a standing ovation by the fans and his own teammates.
It is widely believe this will be the final game of Ilicic’s career, certainly with Atalanta, but also retirement seems to be on the cards for the 34-year-old.
He played 172 competitive games for Atalanta, scoring 60 goals and providing 44 assists.
Ilicic also played for Fiorentina and Palermo in Serie A since coming to Italy in August 2010.
𝗣𝗟𝗔𝗬𝗘𝗥𝗦 🫂 𝗙𝗔𝗡𝗦
— Atalanta B.C. (@Atalanta_BC) May 21, 2022