England-based Kelechi Iheanacho and Frank Onyeka as well as Enyimba goalkeeper Olorunleke Ojo are awaiting entry visas to Portugal, officials said.
Newly called up Fisayo Dele-Bashiru and Israel-based goalkeeper Adebayo Adeleye have experienced flight snags no thanks to the war in the Middle East.
Super Eagles spokesman Babafemi Raji said the tickets of the players have had to be re-routed.
The team have already been hit by late withdrawals of Taiwo Awoniyi, Ola Aina and Jamilu Collins.
The Super Eagles take on Saudi Arabia Friday in Portugal, while they tackle Mozambique in another friendly Monday.
Nigeria are getting set for 2026 World Cup qualifiers against Lesotho and Zimbabwe next month.