The United striker spoke to Sky Sports after the 2-0 defeat to City at Old Trafford but Giggs wasn't overly impressed.
Ryan Giggs has criticised Marcus Rashford over his interview after the Manchester derby.
Rashford fronted up to the Sky Sports cameras after United were beaten 2-0 by rivals City at Old Trafford.
The England international called on his team-mates to remember what it's like to represent Manchester United as they face a fight to make the top four.
Rashford appeared in his United tracksuit after the game and was also wearing a branded Dsquared2 cap for the interview.
United legend Giggs questioned Rashford's decision as he appeared on punditry duty for Optus Sport."He's a young player, we've all done it… an interview after the game, you're emotional, you're not happy," Giggs said.
"I don't know why he's wearing that cap, but that might be just me – old school, not like the modern footballer now.
"He's upset, he says he think they're good enough – they're not good enough."
Rashford had admitted United have plenty of work to do after their recent poor run of results.
"We have to be real with each other. It's a matter of trying to improve each other. We've shown we can do it.
"That's what's the most disappointing thing because we're not doing it.
"Forget top four, forget Champions League. It's about being Man United again and playing like we know we can."
But Giggs suggested the defeat just highlighted the gulf in class between the two teams.
"United, because of the first touch, or not good enough, because of the options they have, they just kick it long and it's not good enough.
"We haven't got as good players as Liverpool and Manchester City ."