The Citizens thrashed the Red Devils 3-1 at Old Trafford.
Ole Gunnar Solskjaer said Manchester United's first half display against rivals Manchester City in the EFL Cup on Tuesday night was abysmal.
It was the worst performance from the Red Devils this season as they were thrashed 3-1 in first leg of the semi-final at Old Trafford, thanks to first half goals from Bernardo Silva and Riyad Mahrez and an own goal from Andreas Pereira.
Marcus Rashford pulled one back for United in the second-half but the hosts were unable to secure a comeback.
Solskjaer was clearly disappointed with the way his players performed on the night and he told a news conference after the defeat as the Independent reported: "From their goal until half-time it's the worst we've played.
"Before then, it could've gone either way, a goal, but that doesn't matter now.
"We've just got to focus on Saturday, Norwich [City]. After that second half we've got something that we can believe in."
The Norwegian revealed what he told his players at half-time: "Pride is one word that you speak about at half-time.
"Make sure you win the second half and you're in the tie and of course it's a difficult task that we've got in front of us.
"But that second half at least gave us something to hang onto."
The second leg of the semi-final will be at the Etihad Stadium on January 29.