Gernot Rohr has refused to comment about his future as Nigeria coach following further speculation over unpaid salary.
The 66-year-old German, who has a contract until June 2022, has had late salary payments since he took charge of the Super Eagles in August 2016.
The Nigeria Football Federation (NFF) admitted that Rohr is owed a September salary - and not three months as widely reported - amid talk that Sunday's friendly against Brazil in Singapore could be his last game in charge.
"I cannot talk about my future now, let's concentrate on the Brazil game and not me," Rohr told BBC Sport.
"It is late here in Singapore and this game can help us prepare for the two Nations Cup qualifying matches in November.
"After late arrivals of delegation, two players and equipment, we are finally ready for the big friendly on Sunday."
The former Gabon, Niger and Burkina Faso coach qualified for the 2018 World Cup in Russia where the three-time African champions failed to make it past the group stage.
He led them to a third place finish at the 2019 Africa Cup of Nations in Egypt.