Gernot Rohr, who was sacked as Nigeria coach on Sunday, believes the Super Eagles can have a successful Africa Cup of Nations.
"It's a huge frustration, but I don't want to argue, it's not my style," Rohr told AFP.
"(I'm) convinced they will have a very good Nations Cup because the team is in place, and this very united group is ready for the challenges that await it."
Rohr, who was Nigeria's longest-serving manager after taking charge in August 2016, had led the Super Eagles team to both Africa's 2022 World Cup play-offs and qualification for the Nations Cup.
However, he was criticised for poor results against lower-ranked opponents during the World Cup qualifying campaign, which included a 1-0 home defeat by Central African Republic.
"I'm going to have a hard time without these great players and this very united staff, but the environment is not always favourable, we cannot control everything," Rohr said.
The Franco-German led Nigeria to the 2018 World Cup and guided the team to third place at the 2019 Africa Cup of Nations in Egypt.
Napoli and Super Eagles striker Victor Osimhen tweeted a message of support for Rohr following his departure.
"Thank you for everything coach and I wish you all the best," said the 22-year-old, who is a doubt for the Nations Cup after suffering a facial injury last month.
Nigeria have been drawn in Group D for the tournament, which begins on Sunday, 9 January, alongside seven-time champions Egypt, Sudan and Guinea-Bissau.