Premier League Preview: West Brom v Man City
Pellegrini selected James Milner as an auxiliary striker in last weekend's 3-0 home victory over Crystal Palace in the absence of Sergio Aguero, Edin Dzeko and Stevan Jovetic.
Though the latter returned to training ahead of the champions' trip to The Hawthorns, he will not be fit to play, meaning Pellegrini once again has to conjure up something different.
Milner may well feature up top again with youngsters Jose Angel Pozo and Thierry Ambrose seemingly the Chilean's only other viable options.
Frank Lampard would offer a goal threat if selected, and Pellegrini revealed in the build-up to this game he is hoping to secure the former Chelsea man's future at Eastlands over the festive period on a longer-term loan from New York City.
Despite their injury woes, City were clinical against Palace, scoring with all three of their shots on target, and Pellegrini believes they may be returning to their title-winning vintage.
"It is always hard to win, the first time and the second time," Pellegrini said.
"Maybe when you already win one title, at the beginning of the season, especially after a World Cup, maybe it is a bit difficult.
"But after that, I think that is the same degree of difficulty from one year to another.
"We are playing now again with the intensity and in style of play we always do, though.
"We again have the players in high level of performance and good moments. We are trusting in what we do, so in the same way maybe we play in a poor way two months ago, we are doing very well."
As well as City's strikers, captain Vincent Kompany (hamstring) once again misses out, but four consecutive clean sheets in all competitions - with only one featuring the skipper - will enthuse Pellegrini, and Gael Clichy's return from a foot issue is another boost at the back.
Pellegrini's counterpart Alan Irvine expects long-term absentee Jonas Olsson (Achilles) to be his only player missing for the champions' visit as he continues to tinker with his own attacking forces.
A front three of Silvestre Varela, Stephane Sessegnon and Brown Ideye impressed in the early stages of Saturday's trip to QPR as Albion raced into a two goal lead before Charlie Austin's hat-trick turned the game on its head.
Though naturally disappointed with the result, Irvine believes he may have found the right formula with his attacking selection.
He said: "We need this game to move on from last week. We have to learn from what went wrong at QPR. It's still galling that we got nothing.
"The three up front worked well, but it's something we could only put together recently.
"Silvestre was like Brown, in that he missed pre-season and got injured.
"Sess has played most of the games and played in differed positions but that three up front look a handful and we're pleased how they're progressing."