Borini faces three months out
Borini first sustained an injury to his foot in the Reds' 2-1 home defeat by Manchester United on 23 September, Liverpool said in a statement on their website.
The club said the 21-year-old then "aggravated the problem resulting in a fracture" when on international duty with Italy's U-21s ahead of their game against Sweden on Friday.
"Typically, an injury of this nature requires a three-month rehabilitation period," the statement added.
His absence leaves the club with just one recognised striker in Uruguayan Luis Suarez.