Louis van Gaal has branded Chris Smalling's actions during this afternoon's Manchester derby as "not very smart".
The Manchester United centre-back was dismissed during the first half for two bookable offences before Sergio Aguero scored the winner for Manchester City.
He was initially cautioned for attempting to stop City goalkeeper Joe Hart from making a quick clearance, while his second yellow came after he had fouled James Milner.
When asked about referee Michael Oliver's decision to red card Smalling, Van Gaal admitted that the 24-year-old deserved his marching orders.
"The first yellow card for Chris Smalling, I did not see but OK, the referee gives a yellow card. You know as a player you have a yellow and you cannot do what he did for the second yellow card. That is logical," he told BBC Sport.
"I say a lot of things to the players and despite that they do not always follow what I said. There is also emotion and sometimes you cannot control your emotion but it was not very smart."
The dismissal was England defender Smalling's first red card of his professional career.
No Data Analysis info
Germany
Switzerland
Hungary
Scotland
Spain
Italy
Croatia
Albania
England
Denmark
Slovenia
Serbia
Austria
France
Netherlands
Poland
Romania
Belgium
Slovakia
Ukraine
Portugal
Turkey
Georgia
Czech Republic