Giovanni van Bronckhorst pleaded with Feyenoord supporters not to cause trouble in Manchester on Thursday.
Thousands of fans - including 200 known hooligans - have travelled to the North West without tickets for the Europa League clash with Manchester United.
Police believe they could congregate in the city centre and Sportsmail understands those with tickets in the away end will be marched towards Old Trafford together.
Van Bronckhorst does not want Feyenoord's healthy contingent to overshadow the fixture.