River Plate coach Marcelo Gallardo wants his players to show passion and belief in order to spring a shock against Barcelona in Sunday's Club World Cup final.
Spanish and European champions Barca are favourites to add the world crown to their list of titles collected during a phenomenal 2015.
"We made a great effort to be here – it has been a long journey and we have given everything," Gallardo told a pre-match news conference in Yokohama.
"This game is not only important in the history of River but in the history of Argentine football.
"It's a great challenge for us. Barca are the best in the world right now.
"They have the best players but we have a big heart. It is a duel of the highest level.
"We will enjoy the game because it is an opportunity that occurs once in a lifetime."
Barcelona cruised to a 3-0 semi-final victory over Guangzhou Evergrande Taobao thanks to a Luis Suarez hat-trick.
The club's other star forwards, Lionel Messi and Neymar, were absent through illness and injury respectively.
"I would like to play [against] those two," he added. "For me it is a pleasure to deal with two of the three best players today."
