Leeds United boss Marcelo Bielsa expects a stern test on Sunday against Sheffield United.
Leeds have taken four points from their first two games back in the top flight, while the Blades are bidding to kick-start their season after successive defeats to Wolves and Aston Villa.
But Bielsa expressed his admiration for Blades boss Chris Wilder and his side following their top-10 Premier League finish last season.
"They are a very good team and have consolidated and it's a good opportunity to compare ourselves to them," Bielsa said.
The 65-year-old, who has managed in Mexico, Spain, Italy and France, said he had yet to witness a more fierce rivalry than the one between former club Newell's Old Boys and Rosario in his native Argentina.
"In all the derbies I've watched or coached in or analysed, I've never seen an intensity or an importance that is (comparable to) the game between Newell's and Rosario," he added.