The forward, who made his first appearance for La Roja in Wednesday's friendly after changing his international allegiance from Brazil, tussled with the defender on numerous occasions when Atletico Madrid clashed with its derby rival last weekend in a physical 2-2 draw.
However, the 25-year-old insisted there is no animosity between the two and instead says they are now extremely close.
"Sergio Ramos and I are almost like brothers now," Marca quotes the striker as saying.
The Atletico talisman added that he was delighted to have received his first cap with the Spanish national team, although he was disappointed not to have scored.
"I got the monkey off my back by making my debut. It would have been a dream to mark it with a goal, but it wasn't to be - I'm really happy anyway."
The striker is now eying a spot in the Spain team for the World Cup in his native country this summer, but to do so he feels he must remain focused on club duties and keep his performances at a high level.
"Now I have to focus on Atletico, where I have to keep doing well to keep my place in the Spain squad. Everyone knows I was born in Brazil but I wanted to play for Spain. I won't forget the affection they've shown me."