Manchester United were the dominant team in English football for almost two decades, but neighbours City have left them behind recently.
Ole Gunnar Solskjaer wants his Manchester United players to strike another blow in Tuesday's derby against a Manchester City team who have "raised the bar so much" in English football.
A month on from stunning City at the Etihad Stadium with a 2-1 victory in the Premier League, United will have home advantage in the first leg of the EFL Cup semi-final.
There remains little doubt where the power lies in Manchester, with City emerging as the dominant side in the north-west hotbed over the past decade by winning four of the last eight league titles.
United continue to rebuild after the end of the Alex Ferguson era, with Solskjaer currently the manager trusted with producing a successful Red Devils side.
The Norwegian said: "It's a different era and a different time.
“We are still, in our own heads, one of the biggest clubs in the world but it’s going to take time.
"We have been up and we’ve been down but we’ve always come back."
The leadership of Pep Guardiola over the last three and a half years has taken City to a new level, and they are defending the EFL Cup after last season's domestic treble.
"They've raised the bar so much," Solskjaer told reporters. "It's something to aim for."
While Solskjaer may have learnt plenty from his own time as a player under Ferguson, former Barcelona boss Guardiola has taken his tactical lead from another former Nou Camp chief in the late Johan Cruyff.
The United manager added: "Pep has had a big influence and, since he took over Barca, I've admired his teams.
"You do see one of the best managers ever and you can see where he has taken his wisdom from.
"I had the pleasure of speaking and meeting Johan [Cruyff] back in the day when Jordi [Cruyff, the former Manchester United midfielder] was here and you can see certain similarities."