Liverpool's 3-2 win at Norwich on Easter Sunday means City sit nine points behind the Reds, albeit with two games in hand, ahead of Monday's encounter with West Brom.
Pellegrini's side were held to a surprise 2-2 home draw by bottom club Sunderland in midweek - a result the Chilean blamed on lingering effects of a 3-2 defeat by Brendan Rodgers' side just days earlier.
But he shrugged off suggestions that Liverpool's continued charge could further sap motivation against the Baggies.
"No, I think it was more difficult between Liverpool and Sunderland," Pellegrini said. "Now we have more time for the team to recover.
"I think that we are all conscious that we cannot play in the same way that we played against Sunderland.
"And I think it will not be so difficult (to raise players' spirits) as for the last game."
Liverpool's victory at Carrow Road was their 11th in a row but Pellegrini predicted further late twists, as Sunderland again provided with a shock win at Chelsea.
"I am absolutely sure the other teams will drop points in the same way we did in the last game," he said.
"We have 15 more points to play for and we will try and win the most amount of points.
"The game against Sunderland was a disappointment because we always want to win but, as I said before that game, playing against relegation-threatened teams during the last games of the season is not easy.
"It happened with Everton against Crystal Palace and with us.
"The performance in every game is very important and I hope we are going to improve our performance against West Brom."