Last weekend, the Spanish government came under criticism for a heavy-handed clampdown on Catalan citizens over a referendum on independence from the rest of the country.
Pique has been an outspoken advocate of Catalonia's independence from Spain, leading to fans of the national team abusing the Barca centre-back during a training session on Monday night.
On Wednesday, reports claimed that the Roja defenders had fallen out over the Catalan star's public political views, and that they were not on speaking terms.
Ramos, however, is quoted by Sky Sports News as saying: "Fans have the right to express their opinion. They are free in that regard.
"We have a great relationship, despite our different viewpoints and personalities. Mixing politics and sport is a mistake.
"As a Spaniard, I don't like what's happening, but let's hope it all gets resolved quickly and we can get back to living in a free democracy and enjoying sports, which is what makes us all happy."
Spain booked their spot at the 2018 World Cup courtesy of a 3-0 win over Albania in their penultimate Group G clash on Friday night.