Cape Town - Super Eagles coach Stephen Keshi fired a warning at Bafana Bafana claiming Nigeria are getting stronger with each game they play at the 2014 African Nations Championship tournament.
"I prime my work on the mental (aspect), which I do all the time - more tactical, positional play, because they need to understand the system," Keshi said.
"I'm so happy with the players because they are getting it quickly, so I think we will get better and better as the tournament goes on."
The Nigerians began their campaign with a 1-0 loss to Mali and were then given a fright by an adventurous Mozambique side before winning 4-2 on Wednesday night.
The victory sets up a tantalising final Group A match with South Africa on Sunday. Nigeria must win the game to ensure they make the quarter-finals, while a draw would be enough for Bafana Bafana to go through.
Coming into the tournament, Keshi had relatively little time to work with a squad made up of domestic players from the Nigerian league, most of them with very little international experience.
It showed as a disjointed performance resulted in defeat to west African neighbours Mali. It was, however, a far more clinical and composed Super Eagles which scored two goals without return in the second half of the Mozambique match after it was 2-2 at half-time.
Keshi's biggest challenge has been to awaken his players from what would normally be a mid-season slumber period, the Nigerian Premier League having been in recess for the last few months. But he feels they are ready to fire on all cylinders against Bafana on Sunday.
"When the players come from out of season it's very tough, not playing for three, four months, very difficult. You could see that the potential is there. But you have to go back to the A, B, C of football," said Keshi, who won the African Cup of Nations as a player and as a coach.
"Sometimes you have to go to the board to explain tactics. I must tell you it's very difficult, but I'm happy with the players."
It would be a big challenge for his team to beat the host nation in Cape Town on Sunday, he said. Nigeria could win the game if they remained properly focused for the entire 90 minutes.
"We'll see what happens on Sunday. Bafana has a very good team - Siphiwe Tshabalala, Itumeleng Khune and Bernard Parker - they are experienced players and they can change the game any time. So it's going to be a very difficult but we will try and do our best.
"I have watched both their games, and they have what it takes. So we must be very, very focused. The concentration level of our team needs to be high to withstand them. And they have a very good coach, that's my problem. The coach has to go home."