Diaw had been placed on the stand-by list by Cisse and will step in for Gassama who lasted 35 minutes last Friday. This was when his Turkish Super Lig side Goztepe lost 3-1 to Kasimpasa.
Gassama was forced off after sustaining a groin injury. Diaw’s call-up sees the more experienced Nantes defender Kara Mbodji once again being overlooked.
Senegal are on top of Group A with four points, although they dropped two points last month after they were held 2-2 away in Madagascar.
Cisse and his men would be seeking to maintain their lead and an unbeaten run in the qualifiers. Their opponents Sudan are struggling after losing their first two games.
The first match against Sudan is on Saturday, before playing them again away in Khartoum three days later.