Newcastle get unexpected boost ahead of January
The Newcastle United defender had been in line for a call-up to the tournament, which kicks off next month.
But Lazaar, signed from Palermo in the summer, has been left out of Morocco's 26-man squad.
The 24-year-old has only made a handful of appearances for the club this season.
And Lazaar is yet to start a Championship match.
However, United are still likely to lose three players to the Cup of Nations, which is being staged in Gabon.
Mohamed Diame (Senegal), Chancel Mbemba (DR Congo) and Christian Atsu are all expected to be called up by their countries.
Cheick Tiote could also get called up by the Ivory Coast.