An original list of 28 players, for the 17 January to 8 February showpiece, has been whittled down to a maximum of 23 but Frenchman Giresse can still alter his final squad within 48 hours of their opening match against Ghana on 19 January.
"Sadio Mane is in the list of 23 players, he has a muscular problem and we will wait until January 11 in order to make a final decision," Giresse told a press conference about the Southampton player on Monday.
"We'll make a decision once we've consulted the doctors," added the former international midfielder. West Ham United's Sahko is carrying a back injury picked up on 1 January, the same day as Mane, and also remains questionable.
Senegal will continue their preparation in Morocco, the original 2015 host country before being replaced by Equatorial Guinea, and will play fellow qualifiers Guinea on Friday and Gabon on 13 January.
Also in Group C with Senegal are South Africa and Algeria in arguably the toughest pool in the tournament.