Nigeria had already qualified for next year’s finals in Russia with Moses a key figure, but the 26-year-old suffered the injury in Chelsea’s loss to Crystal Palace two weeks ago.
Rohr called up 20-year-old forward Onyekuru, who has scored seven goals this season on loan at Anderlecht from Premier League club Everton and made his international debut in a friendly against Togo in June.
German coach Rohr also handed first call-ups to Norway-based Chidiebere Nwakali and young goalkeeper Francis Uzoho from Spanish club Deportivo La Coruna.
The Super Eagles take on Algeria in Constantine on November 10, before flying out to Russian city Krasnodar for the friendly with Argentina on November 14.
Goalkeepers: Daniel Akpeyi (Chippa United/RSA), Ikechukwu Ezenwa (FC Ifeanyi Ubah), Francis Uzoho (Deportivo La Coruna/ESP)
Defenders: William Troost-Ekong (Bursaspor/TUR), Abdullahi Shehu (Anorthosis Famagusta/CYP), Tyronne Ebuehi (ADO Den Haag/NED), Leon Balogun (Mainz 05/GER), Uche Agbo (Standard Liege/BEL), Chidozie Awaziem (Nantes/FRA), Ola Aina (Hull City/ENG)
Midfielders: Mikel John Obi (Tianjin Teda/CHN), Ogenyi Onazi (Trabzonspor/TUR), Wilfred Ndidi (Leicester City/ENG), Oghenekaro Etebo (Feirense/POR), John Ogu (Hapoel Be’er Sheva/ISR), Mikel Agu (Bursaspor/TUR), Chidiebere Nwakali (Sogndal/NOR)
Forwards: Ahmed Musa (Leicester City/ENG), Kelechi Iheanacho (Leicester City/ENG), Moses Simon (Gent/BEL), Alex Iwobi (Arsenal/ENG), Odion Ighalo (Chang Chun-Yatai/CHN), Henry Onyekuru (Anderlecht/BEL), Anthony Nwakaeme (Hapoel Be’er Sheva/ISR)
Standby: Kenneth Omeruo (Kasimpasa/TUR), Alhassan Ibrahim (Austria Vienna/AUT), Brian Idowu (Amkar Perm/RUS)