Morocco start their Group C campaign against DR Congo on Monday, then face Togo on 20 January and take on Ivory Coast four days later.
Rherras, 23, and Cameroon midfielder Arnaud Djoum, 27, will miss Hearts' Scottish Cup meeting with Raith Rovers on 22 January.
Cameroon are in Group A with Burkina Faso, Guinea-Bissau and hosts Gabon.
Djoum has five international caps while Rherras made his Morocco debut in August.
Scottish Premiership clubs are currently on their winter break and Hearts' next league fixture is away to Celtic on 29 January.Local photographer Ron Strathdee captured the phenomenon on Monday at about 23:30 BST.
The glow is usually best seen from northern latitudes like Norway, Alaska, Iceland and northern Scotland.
Mr Strathdee said seeing the Northrn Lights from Manx latitudes was "fairly unusual."
They happen when incoming solar radiation hits the earth's upper atmosphere and excites atoms to a new energy state, emitting energy in the form of light.
The photographer said: "I needed a place that faced north so went to Peel Hill and tried some shots over the castle which worked but half the fishing boats in the Irish Sea were discharging fish at the breakwater with enough floodlights to cover a football match!
"Going round the front of the castle it was pitch dark and it looks straight north