Verstappen's finish to 2018 was quite incredible - with only Hamilton, who went onto win the championship, finishing with more points over the last nine races of the season.
Red Bull are switching to Honda power units for 2019, ending their partnership with Renault, after a faulty season. Many are expecting Red Bull to be right up there in terms of the final leaderboard.
If Honda can deliver with the side from Milton Keynes, Horner is predicting that the Dutch 21-year-old could have a psychological advantage over his rivals.
"Max, if you look at his performance in the second half of (last) year, was the second highest points scorer to Lewis," Horner told the press. "He has the skills to take on Lewis or Sebastian or whoever it is.
"I don't think he lacks anything that they have, if we can provide him the tools to do the job. I think he's probably the driver they fear the most.
"Max has evolved so much. He is more worldly, more experienced. He is very quick and very determined and has his own character. He is now in a very rounded position. He has absolute determination and zero fear."