The seven-time winner of Europe's premier club competition already had Ignazio Abate, Mattia De Sciglio, Matias Silvestre, Daniele Bonera and Giampaolo Pazzini sidelined prior to its 2-2 draw with Torino.
Tweet Ruud Gullit!
Celtic's quest to reach the last 16 of the UEFA Champions League starts at AC Milan where the Scottish champions will attempt to win in Italy for the first time.
The Bhoys' European adventure came to an end at the hands of Juventus last season in the first knockout stage, but Neil Lennon's side face an uphill battle to make it past the group phase this time around.
In the only group which contains past European champions, Celtic must also meet Ajax and Barcelona after navigating through three qualifying rounds to simply reach this stage.
The Rossoneri will be down to the bare bones for the Celtic clash, and coach Massimiliano Allegri told the club's official website: "We'll make do with who we have and we'll have fresh players ready to play what is a delicate and important game."
Allegri's men have won just one of their first three games in Serie A and only salvaged a point at Torino courtesy of late goals from Sulley Muntari and Mario Balotelli.
A similarly slow start in European competition could well prove costly, as Milan has been drawn in a difficult Group H that also features Barcelona and Ajax.
Celtic will be aiming to follow up last season's impressive showing in the Champions League, which was highlighted by a shock 2-1 home victory over Barcelona.
Victor Wanyama scored the opening goal of that game, but he has since departed to Southampton, while star striker Gary Hooper also left the club this summer to join Norwich City.
One of Celtic's summer additions, fullback Steven Mouyokolo, is set to miss the entire group stage after rupturing his Achilles tendon in training, while winger James Forrest returned from international duty with Scotland nursing a back complaint.
