Santon impressed for Newcastle last season while Haidara, who joined the club in January, also showed promise during eight appearances either side of an injury.
And with both battling for a place on the left-hand side of the Magpies' defence, Haidara believes the rivalry will only benefit Alan Pardew's team as a whole.
"Competition amongst players can only bring the best out in you, and that then has a knock-on effect to bring the best out in the team as well," said the 20-year-old.
"When you've got someone who's just as good in your position then it is healthy. It makes you never give up - you give 100 per cent every single time you are on the pitch or the training pitch.
"And if everyone is giving 100 per cent then it can only benefit the team."
Despite Paul Dummett and Shane Ferguson also providing Pardew with options at left-back, Haidara knows only the best player will make the cut.
"Davide and me get on really well off the pitch. On the pitch, the best man is going to play at the end of the day," added the Frenchman.