Nigeria coach Stephen Keshi has acknowledged FIFA World Cup opponents Iran are something of an unknown quantity.
The nations meet in their Group F opener on Monday, with the most realistic aim for both likely to be a second-place finish behind Argentina.
Avoiding defeat against Carlos Queiroz's men could prove vital in avoiding an early elimination but former Nigeria international Keshi is in the dark as to what threat they will pose.
Iran have never made it out of the group stage at a World Cup but Keshi is mindful of the experience of their coach and the danger possessed by some of their players.
"We have to go out with everything that we have. They have a very good coach and I'm sure they also have some quality players," he told FIFA.com.
"We don't know Iran very well, but we'll see them on Monday."
Quieroz has managed a host of nations including South Africa and Portugal as well as a stint as coach at Real Madrid.
This kind of know-how is something that Keshi believes will stand Iran in good stead when the nations meet in Curitiba.
"I think an experienced coach is their biggest weapon. He's well experienced, he knows the game well," Keshi added.
"For the Iran game we have to be focused. We have to concentrate and do our job. We're not going to take Iran lightly because they're not going to take us lightly."comments