This idea that Rodri plays on his own is ridiculous. Same as Fernandinho. They've both always been massively supported by fullbacks coming inside or a midfielder dropping deep. It might be a 1 on paper but it's a 2 in practice.
In fact, BOTH players have suffered from times where they were isolated since Pep arrived. Chelsea in the FA cup (Fernandinho) and Chelsea in the league (Rodri) are recent examples of this.
And this won't go down well, but of the two Rodri handled himself better, barring one admittedly bad moment.