Brentford boss Thomas Frank was unhappy with fans booing Christian Eriksen yesterday.
The former Bees was jeered as he turned out for Manchester United.
After Brentford's 4-0 win, Frank said: "I understand why fans can react that way, but personally I think that we as a club must show class, respect and integrity in everything we do. That's what I try to do every single day.
"I think we have to remember that not all fans did it. But I think any player that comes back - it doesn't have to be Christian, it could be Neal Maupay or Ollie Watkins - we should applaud when they come back the first time.
"Of course it's banter when you can sing a little, but booing a player? It is not class, and I would never do that myself."