Galatasaray forward Osimhen will miss the upcoming encounters after undergoing surgery last week and is expected to be out of action for a number of weeks.
Meanwhile, Iheanacho has been surprisingly left out of the squad despite his eye-catching form in the Turkish second division for Bursaspor, where he has scored 17 goals and registered three assists in 14 matches.
The 30-year-old featured and scored in his last appearance under Chelle in the 3-3 international friendly against Russia last month but has seemingly failed to secure a spot in the current Super Eagles squad.
Nigeria are set to host tournament co-hosts Tanzania at the Godswill Akpabio Stadium in Uyo on Friday 13 November before travelling to play the Taifa Stars at the Amman Stadium in Zanzibar on Tuesday 17 November.
Both matches are crucial for the second-placed Nigerian side which will be looking to bounce back from a 3-0 humbling by Group L leaders Guinea-Bissau in their last qualifier.
Full Super Eagles squad:
Goalkeepers: Arthur Okonkwo, Francis Uzoho, Stanley Nwabali
Defenders: Bruno Onyemaechi, Olaoluwa Aina, Benjamin Fredricks, Oluwasemilogo Ajayi, Calvin Bassey, Chibuike Nwaiwu, Bright Osayi-Samuel, Abdullahi Bewene
Midfielders: Wilfred Ndidi, Alex Iwobi, Alhassan Yusuf, Tochukwu Nnadi, Samson Tijani, Fisayo Dele-Bashiru, Mubarak Suleiman
Forwards: Moses Simon, Taiwo Awoniyi, Akor Adams, Ademola Lookman, Tolu Arokodare, Moses Usor