The Foxes have had to operate with a larger squad in the Premier League this season, meaning that several players have not experienced much first-team action so far.
Pearson has accepted that he will have to deal with some disappointed players this term.
"In terms of keeping players happy, I accept it is impossible to keep them all happy but it is important to show a level of fairness, and that the selection process has a rationale behind it," he told the Leicester Mercury.
"If you do that correctly, you have a better chance of keeping people on side.
"I am not here to be the players' friend. I am here to be the manager of the football club and it is my job to make decisions on what I feel is the best side to take on whoever we are playing."
Leicester travel to Newcastle United on Saturday.