"Of course, if you ask me at this moment, the game against Arsenal next weekend is more important than the game against Bayern Munich," Pellegrini told reporters.
"From the moment we qualified for the next round, the Premier League became more important than Champions League.
"I will not change my tactics. Maybe because we are playing away, I do a different thing but, if I was to play that game again, I would do exactly the same," Pellegrini said of the 3-1 defeat by Bayern in October.
He confirmed that England goalkeeper Joe Hart, dropped after a poor game against Bayern and other high-profile errors, will start the match at the Allianz Arena ahead of Costel Pantilimon.
Pellegrini plans to rest other key players but did not name them.
"That does not mean there is a possibility that the players who play against Bayern Munich will not play against Arsenal," the Chilean added.
(Reporting By Tony Goodson, editing by Ed Osmond)
