South American champions River Plate must maintain concentration in Tuesday's Club World Cup semi-final against host side Al Ain FC after a tumultuous two weeks, the Argentine side's coach Marcelo Gallardo said on Monday.

River Plate have travelled to the United Arab Emirates after triumphing in the second leg of the Copa Libertadores final against fellow Argentine rivals Boca Juniors which was moved to Madrid following fan violence in Buenos Aires.

They are expected to cruise past Al Ain for a probable final against Real Madrid but Gallardo is warning against complacency.

"It is going to be a tough match," he told journalists. "They have shown they deserve to be in the semi-final."

Al Ain put three past Tunisia's Esperance in Saturday's quarter-final, convincingly beating the African champions.

However, Al Ain's tournament got off to a shaky start when they were taken to penalties by semi-professionals Team Wellington FC on Wednesday in the tournament's only playoff.

Gallardo said River Plate were taking the semi-final clash very seriously, warning that host nation champions Al Ain were a "dangerous team when attacking."

He also paid them the compliment of saying his side would be man-marking Al Ain's Brazilian midfielder Caio. "He is a very important and interesting player for his team," he said.

Al Ain will be looking to go one better than fellow UAE side Al Jazira Club who lost 2-1 in last year's semi-final to Real Madrid. "We have an opportunity to write history," said their coach Zoran Mamic.

No UAE side has ever made it to the Club World Cup final.

Real Madrid meet Asian champions Kashima Antlers in the other semi-final on Wednesday night, a rematch of the 2016 final which the Spanish side won in extra time.

The final will be held on Saturday in Abu Dhabi.