Claudio Ranieri warned his Monaco squad not to lose focus against a Reims side that has lost just one game this season.
Monaco have yet to taste defeat in Ligue 1 this season, winning five and drawing two of their seven matches to sit atop the table.
Ranieri’s men have enjoyed a fruitful week with a valuable 1-1 draw against reigning champions Paris Saint-Germain coming on Sunday, when Radamel Falcao cancelled out Zlatan Ibrahimovic’s opener.
And the Colombian continued his purple patch in front of goal with a brace in the 3-0 triumph over Bastia on Wednesday.
But Reims have proved difficult opposition in the league this year, with victories over Lyon and Lille to their name.
And Ranieri urged the squad to be vigilant when the two sides square off on Sunday.
“Reims have the second best defence in Ligue 1,” he said. “Their organisation is very good.
“They beat Lille and Lyon and have lost just once, it will be difficult.
“Moreover, this game comes after three games in a week. Concentration will be very important.
“We conceded too many shots against Bastia, we must work on that too.”