Manchester United manager Louis van Gaal has hit out at Chris Smalling after his side's derby loss to Manchester City on Sunday.
Defender Smalling was sent off six minutes before half-time after he was shown a second yellow card as the Red Devils went down 1-0 at the Etihad Stadium.
The first caution came for a cynical block on City goalkeeper Joe Hart before referee Michael Oliver brandished another card for a sliding challenge on James Milner which prompted the following words from van Gaal.
"In a derby you have to be careful - the second yellow card is a stupid yellow card," he told BBC Sport.
"As a player you have to control your aggression.
"I didn't see the first yellow but with the second, you know you already have a yellow, so have to handle it differently. I said that to the players.
"You have to deal with that. You cannot do what he has done with the second yellow card. That is not very smart."
When asked if Smalling had apologised for his actions, van Gaal added: "He said it very humbly. You can only accept it. But nevertheless it was in my opinion not so smart."
Sergio Aguero scored the only goal of the contest with a 63rd-minute effort as reigning champions City remained third on the table, six points leaders Chelsea, with United falling to 10th.
