Manchester United were named as the underdogs for the Premier League clash against Manchester City at the Etihad Stadium.
United put in a good performance in the first half against City, and were unlucky to be 2-1 down at half-time.
However, the second half display from the team was shambolic, as United conceded two more goals.
Roy Keane slammed Manchester United’s second half performance and admitted that he can’t forgive the players for a lack of effort.
He told Sky Sports: “They did give up. For a player in a derby or any game, it’s unforgiveable really.
“The beauty of top level sport is that there’s no hiding place. We saw all United’s shortcomings today.
“There’s ways to lose football matches, but the way United lost it today, they stopped running, gave up. Players not running back, that’s what I don’t understand.
“The manager will be criticised for the tactics but players not running back when playing for Man United, it’s really unacceptable, it really is. They threw the towel in, it’s shameful.
“It’s hard when you’re out there against a really good team. But you’ve got to run back, got to tackle. It’s a reflection of where the team is and where the club is. It’s so far behind the other teams.”