Poland top the standings on four points and will advance with a win or a draw. But they would be knocked out by a defeat coupled with a victory by Saudi Arabia over Mexico.
"Ever since the groups were drawn, the whole world has been waiting to see this match," Michniewicz told a news conference.
"It's a match between Poland and Argentina, not between Lewandowski and Messi.
"It's not tennis where they're going to play one-on-one and everyone will wait to see who serves an ace or a beautiful lob. Robert needs his team mates, so does Messi."
Argentina have won six out of their 11 games against Poland, while the Poles won the last time the sides met in 2011 in a friendly.
"This match is not a friendly," Michniewicz said. "It's going to be a fight between two teams who both can still progress."
To make it happen, Poland will need to stop one of the world's greats.
"It's a great question, how to stop Lionel Messi," Michniewicz joked. "I think the whole world has been wondering about it for the past 18 years. And I don't think we're going to find out for as long as he's still playing."
The Poland coach went on to compare the Argentine striker to a former Olympic gold medallist in alpine skiing.
"Today at the briefing we talked about Messi acting on the pitch like Alberto Tomba on the slope," Michniewicz said.
"He can avoid everyone like Tomba did, so I need to set up the poles, meaning place our players in a way to make it a difficult ride for him. One player wouldn't stop Messi, we need to do it as a teamwork. But we are ready for it."
Michniewicz added that Poland would not approach the game with a single strategy.
"We don't have one approach. We can't only be defensive, we need to be offensive too," he said.
"Approaching this game hoping for a draw would make us lose because we must assume Argentina will be able to score. That's why we'll want to score from the start too."
But above all, Michniewicz appreciated the experience his players are about to gain.
"I'm really happy because I've been to Barcelona so many times to see football at a top level, to see Messi," he added.
"We should all be excited to play with Argentina, and for a high stake too. We'll respect every result, but will do everything to win because we can.
"No one should feel stressed or under pressure, they should be joyful because it's a great honour for any player, coach to play at the World Cup against Argentina."
