City's fate is back in their own hands after Barclays Premier League leaders Liverpool slipped up at the hands of another title rival, Chelsea, last Sunday.
Pellegrini's men still trail the Reds by three points but have a game in hand and a superior goal difference as the final week of the campaign approaches.
City, whose challenge had suffered a hefty setback with defeat at Liverpool and a home draw with struggling Sunderland last month, will look to press home their advantage by winning at Everton this weekend.
Victory at Goodison Park would take City to the top of the table, a position they have held only fleetingly this season.
Pellegrini said: "Of course, when you just depend on what you can do it is better for all the players.
"After we lost against Liverpool, maybe the mood wasn't the same. That's maybe why we didn't play so well against Sunderland.
"At the moment the motivation is very high, now it is important that the performance also must be high."
Pellegrini is well aware that any more stumbles by his side would open up the door for Liverpool and Chelsea.
But the Chilean does not want to concern himself with results elsewhere and is focusing only on the fixtures he can influence.
He said: "In football you never know, so the only important thing for us was to think about what we can do and the only thing we can do is to try and win our games.
"All the other things are speculation. Maybe the media know what the score will be in a lot of games - for me it is impossible to know."
Pellegrini's next obstacle is Everton, a team which City have had plenty of difficulty against over the years.
City did beat the Toffees 3-1 at the Etihad Stadium in October but it was only a fifth win in 19 meetings between the clubs.
They have lost their last four games at Goodison and won there only once since 1993. Their last league double over the Merseysiders was in the 1980-81 season.
Everton also have an incentive of their own with Champions League qualification still an outside possibility.
Pellegrini said: "I think Everton at any stage of the season will always be a very difficult team, they play very well.
"Roberto (Martinez) is doing a very good job, the same way as he did before at Wigan.
"He is playing for Champions League, he is playing for Europa League.
"We are sure we are going to have a very tough game there."
The one unknown about the occasion could be the Goodison atmosphere, given any Evertonian's natural disinclination to do any favours for rivals Liverpool.
Yet whatever the feeling, Pellegrini does not expect it to affect the mentality of the players.
The 60-year-old said: "It is not what Everton are trying to do on the pitch.
"The feeling outside will not decide the match. I think the Everton players will try to win the game."
City are boosted by the potential return of playmaker David Silva, who missed the win at Palace after suffering an ankle injury in the previous game.
Pellegrini said: "David is a very important player for us. He will be in the squad list."
After facing Everton, City will wrap up their campaign with home games against Aston Villa and West Ham.
The squad will then fly to Abu Dhabi for a post-season trip before disbanding for the summer.
England manager Roy Hodgson has expressed concern about some of his players - potentially Joe Hart and James Milner - travelling with the World Cup looming.
Pellegrini, however, has reiterated a promise those players will not participate in a planned exhibition match against Al Ain.
He said: "For all the players of their national squads - not only for England - the last game they are going to play will be on May 11."