On Thursday, Pique took to social media to back the referendum taking place on Sunday without implying what way he would vote himself. When asked about the post, Ramos said his Spain team-mate's decision to wade into the debate will not earn him any extra favour with fans of the national team.
"Pique's tweet is not the best if you don't want them to whistle," said the Real Madrid skipper, per Juancar Baena of Marca. "Maybe the tweet is not the best for the group either but everyone is free to say what they think."
Ramos was speaking ahead of Spain's upcoming FIFA World Cup qualifying matches, when he is expected to partner Pique in the centre of defence.
Pique's affiliation with Barcelona has led to him being jeered by fans from across Spain when representing the national side at times, particularly when they've played at the Santiago Bernabeu in Madrid.
Here's the post he put on social media in Catalan about the upcoming referendum:
Gerard Piqué @3gerardpique
Des d'avui i fins diumenge, expressem-nos pacíficament. No els hi donem cap excusa. És el que volen. I cantem ben alt i ben fort. #Votarem2017-9-28 10:40:49
"From today and until Sunday, let us express ourselves peacefully," it read, per Reuters (h/t the MailOnline). "We do not give them any excuse. That's what they want. And we sing well tall and very strong."
The referendum is set to be held on Sunday, though as reported by Sam Jones of The Guardian, the Spanish government is seeking to block the ballot as they believe it is illegal.
On the field, Spain have two crucial games coming up as they seek to secure their place at the 2018 FIFA World Cup. Next Friday they host Albania before travelling to Israel on Monday; La Roja currently lead Group G by three points from Italy and need four points from their last two games to guarantee top spot.