Liverpool manager Jurgen Klopp says that "unfortunately a good coach is coming to England" if Manchester United agree a deal with Ralf Rangnick.
Klopp is one of the younger German coaches who looked up to Rangnick and they faced each other as rival bosses.
"United will be organised on the pitch," said Klopp, 54. "That's not good news for other teams."
Rangnick set Ulm on course to promotion to the Bundesliga for the first time before spells in charge of Stuttgart, Hannover, Hoffenheim, Schalke and RB Leipzig.
He has also served as director of football of the Red Bull group of clubs and is currently manager of sports and development for Russian club Lokomotiv Moscow.