Chelsea may play Belletti at left back
Regular left-back Ashley Cole is out with a broken ankle while Russian deputy Yuri Zhirkov limped off in Saturday's 2-0 win at Wolverhampton Wanderers and defender Paulo Ferreira is not on their Champions League squad list.
"We have problems because we are without two good players," former AC Milan coach Ancelotti told a news conference at his old San Siro haunt.
"We have Belletti who can play on the left ... he has been out (injured) for a while but has been training well all week. We will find a solution even if the absence of Cole and Zhirkov will hurt us."
Another option for Ancelotti could be to play left-sided midfielder Florent Malouda in defence.
Inter's Jose Mourinho, the former Chelsea coach, also has left-backs Davide Santon and Cristian Chivu injured.
He had been expected to pick captain Javier Zanetti on the left of the defence but said there was a chance he would play centre-half Ivan Cordoba there so that Zanetti could rampage through the midfield.
Doubts also remained over the fitness of Inter goalkeeper Julio Cesar, who missed training on Monday because of a car crash but practised on Tuesday.
"I'm not sure if he will play," said Mourinho. "I don't know how he will wake up tomorrow.
"After a car accident you don't know how the body reacts 24 hours or whatever later."