Juventus duo Kwadwo Asamoah and Daniele Rugani will be out for between six and seven weeks due to knee injuries, the club have announced.
The pair both pulled up with problems during the 1-0 victory over Palermo on Saturday, which saw the champions maintain their one-point lead at the top of Serie A.
Juve have now confirmed that the duo will be sidelined for 45 days, with Asamoah requiring surgery to correct a meniscus rupture.
"The extent of the injuries sustained by Daniele Rugani and Kwadwo Asamoah were clarified following medical examinations today," a club statement read.
"The tests revealed that Asamoah has ruptured the meniscus cartilage, while Rugani has strained the lateral collateral ligament, both in the right knee.
"The former is expected to undergo surgery with both players anticipated to return within around 45 days."
The duo are set to miss key Serie A clashes with AC Milan and Napoli, as well as three Champions League group games - a visit to Dinamo Zagreb, and home and away meetings with Lyon.
The news is the latest setback for Asamoah, who has been blighted by injury problems over the past two seasons and made just six league starts in 2015-16.
Rugani has played twice this term, scoring in the 4-0 win over Cagliari on September 21.