Pellegrini claims he had a tougher time in his first campaign as City boss and has just been let down by some rudimentary mistakes this term.
Pellegrini's side fell away badly in the second half of the season, tamely surrendering their Barclays Premier League crown to Chelsea after being joint-top in January.
The Chilean is due to meet with club officials to analyse where things went wrong but he insists he has not found the going tougher.
The 61-year-old said: "No, I don't think so
Last season was for me harder than this one because it was my first season here in the Premier League.
"This season, for different reasons, we are not the strong squad we played last year
We made a lot of mistakes - especially against teams who are not in a good position, the teams who are in the relegated positions, we lost nine points against them - and we lost at home in both cups.
"Maybe we will continue being a high-scoring team but we must be a more consistent team that doesn't lose points against teams in the relegated positions."
One area where City have been criticised since winning the title last season is in their recruitment, with none of their main summer signings last year having particularly impressed.
Eliaquim Mangala has been the chief disappointment after his Â£42million move from Porto but Fernando and Bacary Sagna have also made limited impact.
But City were also constrained by restrictions imposed on them by European governing body UEFA for breaking Financial Fair Play rules.
Free of the limitations of a Â£49million net spending cap they could make a greater impression in the transfer market this summer.
Pellegrini said: "Maybe it is not the most important reason why we failed in this season, because we lost a lot of points against teams that are not stronger than our squad, but against Chelsea or Arsenal or Manchester United if you have restrictions and the other clubs don't have them, of course it is an advantage.
"This year we will all be in the same condition and we will see which is the team that works more to have a strong squad."
UEFA president Michel Platini has suggested FFP rules could be eased in future
This would be welcomed at City, who have found their Abu Dhabi-backed spending limited despite being completely debt free.
Pellegrini said: "When we don't have any debt with anyone, I don't see why we have restrictions
It is the thing I am glad to review
I never understand the rules of Financial Fair Play."
Before looking ahead, City need to complete this season
Southampton are the final-day visitors to the Etihad Stadium and after five wins in succession to secure second place, Pellegrini wants to continue the run.
He said: "We must finish here at home trying to win.
"I said to the squad the second position is finished but I don't think the season is finished.
"We have the last game here at home and we must be motivated to win in front of our fans and have a good game and a good farewell to the season
The best way to do it is to win."
Source : PA