Carroll has just made it back from another injury, and made his first appearance of the season in midweek against Cardiff City.
The target-man came off the bench during West Ham’s 3-1 win on Wednesday evening.
And Pellegrini has suggested that Carroll will need to get used to his role of being an impact substitute.
"If he can work in the normal way, of course he can be an option to start in our XI. For the moment, I think he can be a very important substitute,” Pellegrini said.
Carroll has a tough task to break into West Ham’s starting line-up any time soon, as Pellegrini’s other attacking options are in good form.
Javier Hernandez and Lucas Perez have both found the back of the net recently, leaving Carroll facing a fight for a place.
Carroll only has months remaining on his £70,000-a-week contract at West Ham (Daily Star), so needs to impress if he is to earn a new deal at the London Stadium.
The Hammers are next in action at the weekend when they take on Crystal Palace.