City face Borussia Monchengladbach on Wednesday anxious to secure victory after defeat to Juventus in their Group D opener a fortnight ago prompted fresh scrutiny of their European credentials.
Despite excelling on the home front, City have continually floundered on the continent, failing to progress beyond the last 16 in four previous Champions League campaigns.
But Pellegrini, who has surpassed predecessor Roberto Mancini in at least reaching the knockout stages, insisted progress had been made since his appointment in 2013.
The Chilean said: "I don't think we have failed in Europe
In the last two years we have qualified for the next stage and then we lost against the best team in the world, Barcelona
We have beaten Bayern Munich twice.
"Last year were in a complicated situation and we won our last two games.
"So we know how to do it
We just lost a game against Juventus, which was a strange game.
"Now we are trying in the next five games to qualify for the next stage of Europe."
City will have to find a way to succeed without captain Vincent Kompany after the defender, who has missed the last three games with a calf injury, was again ruled out.
In his absence City have conceded six goals in their last three games
Prior to the Juve loss, with Kompany fully fit, they had won five in succession without being breached.
While Kompany did not travel to Germany, there was at least hope over three over players nursing injuries in David Silva, Joe Hart and Yaya Toure
All three were part of the squad and will be assessed prior to the game.
Pellegrini said: "Of course Vincent is a very important player
He is our captain and he has started the season very well but I don't think one player is so crucial
We won the last six games of last season without Vincent."
Pellegrini himself only made the trip on time after an embarrassing late dash back home for the right passport.
The Chilean arrived at Manchester Airport ahead of his squad's chartered flight to Dusseldorf as expected on Tuesday afternoon, but was spotted leaving in a taxi soon after
He later admitted he had blundered over his passport.
"It is not important," he said, trying to laugh off the incident at his pre-match press conference
"I have two passports and I brought the wrong passport."
Pellegrini shared media duties with Kevin de Bruyne who, on a personal level, has made a flying start to his City career after his £54million move from Wolfsburg a month ago.
The Belgian has scored on his last three appearances, but he said he would swap that for a better run of results.
The 24-year-old said: "It is nice to score goals, but I prefer to win to be honest."
Source : PA
Source: PA