Pedro Caixinha’s side lost the first Old Firm clash of the campaign 2-0 recently but will have further chances to measure themselves against the champions over the course of the season.
And Morelos is sure they will be able to compete and eventually get a victory over the Bhoys.
He told the Daily Record: "We didn’t manage to get a favourable result this time, but there are at least three more games against Celtic this season.
"I know we will go and get a good, positive result for Rangers."
He added: "We are close to Celtic in the league and have won our last game. We have a positive mentality and goals in our team."