The African nation will lock horns with Argentina, Croatia and Iceland in the group stages of this summer's tournament in Russia.
Iheanacho is keen to have the "memory" of playing against the Barcelona forward, but the Leicester City attacker is hopeful that his country will "get something" from the clash.
"I've had the opportunity to train with him when I was at the [Manchester] City Academy and he is something else," Iheanacho told LCFC TV.
"I hope we get something against them and he's going to play, so it's going to be something good, a memory to play against Messi. He's one of my idols so I look up to him.
"He's so many people's idol in the world so he's a player you like to play with, to learn something, of course, so I will be happy to play against him. Of course, after 90 minutes, we'll see what happens and hopefully we'll get something."
Nigeria will open their 2018 World Cup tournament against Croatia on June 16, and will also face Iceland before finishing their group campaign against Argentina on June 26.