The Red Devils boss has criticized the 24-year-old English defender for his actions in Sunday's Manchester derby defeat at the Etihad

Many favored Manchester City to beat neighbors and arch-rivals Manchester United when the two sides met at the Etihad in Sunday's highly-anticipated Manchester derby.

However, when 24-year-old English full-back Chris Smalling was given his marching orders in the 39rd minute after receiving a second booking, all hopes of walking away from the match with at least a point evaporated.

Despite the slim 1-0 scoreline, thanks to a 63rd minute winner from leading goalscorer Sergio Aguero, the Citizens numerical advantage gave the home side the edge as they went on to dominate the game, whilst the traveling side fought hard to avoid a huge defeat.

After the game ended, the Red Devils manager Louis Van Gaal admitted to not being pleased with Smalling's actions, saying it was “stupid” and “wasn't very smart”, but went on to hail the 20-time champions' willpower after going down to ten men.

“It had a big influence on our opponents, but also on us,” said the Dutch tactician.

Man United defender Chris Smalling was sent off in Sunday's Manchester derby after picking up a second yellow for this tackle on James Milner

Chris Smalling, James Milner, Manchester City, Manchester United, Manchester Derby, English Premier League

The Red Devils had to play the remainder of the game at the Etihad with 10-men after the 24-year-old defender's 39th minute dismissal, but were able to avoid a huge defeat

Chris Smalling, Manchester City, Manchester United, Manchester Derby, English Premier League

“Despite having 10 men we played better in the second-half than the first, and that’s because of the willpower of the team.

“The sending-off isn’t one of those things. As a player you have to control your ­aggression.

“The first yellow card I didn’t see but, OK, the referee gives it. You know as a player you have a yellow and you can’t do what he did for the second one. That is logical.

“The second yellow card was stupid.

“I say a lot of things to the players and despite that they don’t always follow what I say. There is also emotion and sometimes you can’t control your emotion, but it wasn’t very smart.”

Manchester United, who will face Crystal Palace in their next fixture, a home tie, will have to deal with their current defensive crisis. With Phil Jones, Jonny Evans and Rafael all missing, Smalling will be suspended for the clash with the Eagles, whilst summer signing Marcos Rojo appears to be facing a long spell on the sidelines after dislocating his shoulder in the second-half of the Manchester derby.