The Reds, who finished last season one point behind City in the table and won the Champions League, are eight points clear of Rodri’s side this season, and are the only team in England to have won all of their games this year.
“I don’t know,” he told ESPN FC when asked if the fans saw United or Liverpool as City’s main rivals. “I had never been in the city before, I don’t know how people in the city feel.
“But the team to beat is Liverpool now and that has been for the last two seasons. They are the champions of Europe so everyone wants to beat them, not just us.
“They’re a great team, they have improved a lot of things, they’re a very good team, and they’re the best team in England and in Europe.”
The 23-year-old Rodri acknowledged that he had a steep learning curve to adjust to life at the Etihad and a new role in Pep Guardiola’s side.
He said one of the biggest adjustments was to one of Guardiola’s more controversial tactics.
"I think it's a big challenge for me because I never used to play this position particularly," he went on. "I didn't have this exact role in the team.
"We have lots of offensive players and many other teams try to counter-attack you and a lot of the time you're alone but it's good for me.
"I am learning new things, how to go, when to stay, when I have to do a tactical foul, when I have to jump. It's good for me to learn these things. And for the team it's good because we need those offensive players to be able to play our game."