Pereira, who succeeded Chelsea manager Andre Villas-Boas in June, made five changes to the team who were held by APOEL Nicosia to a disappointing 1-1 home draw in the Champions League last week, with Nicolas Otamendi, Fredy Guarin, Joao Moutinho, James Rodriguez and Kleber all dropping to the bench.
Among their replacements were Belgian midfielder Steven Defour and Brazilian striker Walter who both scored as Porto returned to the top of the championship after briefly falling behind Benfica who played on Saturday.
"This 11 gave a positive response and it proved that our squad has a lot of quality," Pereira said after Sunday's match.
"All players are on equal footing, we must send a message that all players are competing to be picked for each match."
Pereira's Porto have been criticised for failing to show the flair and fluidity that helped them win the Europa League under Villas-Boas last season.
"The fans are demanding but they are always there for us, they deserve today's quality of gameplay," Pereira said.
Despite the criticism levelled at Pereira's side, they still have all to play for in the Champions League, where they are third in Group G, level on four points with Zenit St Petersburg and only one point behind surprise leaders APOEL.
