The Portuguese will send his Manchester United side out against their bitter local rivals at the Etihad on Sunday at the end of a week where Guardiolas team have come under fire after the leaked data exposing their approach to avoiding Financial Fair Play.
While Mourinho would not directly comment on the row, he took aim at Citys recruitment policy and moaned at their superior resources in the transfer market.
I am clearly rebuilding, he said.
In my first season, I got into a situation where there were players like Wayne Rooney and Michael Carrick – phenomenal players and some of the most important players in the past years of the club – coming to the end.
We had to get a player like Ibra [Zlatan Ibrahimovic] to help us to have a certain power to fight for something important, which was clearly to get back to the Champions League level.
But its been hard work, really hard work, with people like Luke Shaw and Tony Martial, for example. Because for talented players like them to get to the level they are now is a process.
To transform talent in professional players into stability and performance is a process of hard work. So is it rebuilding? Yes.
If I need a full-back and I was able to buy four, it would be easier. So, when I needed a full-back, when I wasnt happy with Luke Shaws level, the easiest thing would have been to buy four new players.
Some clubs can buy four full-backs. But we didnt buy a left-back for three years because we were wishing and working for Luke Shaw to be that left-back. But during that process, we played Matteo Darmian, we played Daley Blind, we played Ashley Young, we played Marcos Rojo.
We didnt buy four replacements – and that is a big difference. It takes less time when you buy four full-backs. To buy four, you need good scouting – and you need money.
But to make players well that takes more time.
More: Manchester United FC