The 33-year-old underwent an MRI scan and was diagnosed with a sprained meniscus.
Lippi, who has delayed naming his final 23-man squad until around 2130 local time (1930 GMT), claimed there was nothing to worry about. "Camoranesi felt a pinch in is knee," he said. "It's nothing serious."
The Argentine-born midfielder is one of nine players who won the FIFA World Cup with Lippi in Germany in 2006 still included in the current 28-man party.