What modem do you have?
If its a modem/router combo device, then you could put the R7000 in bridge mode.
but if its a modem only device, the router does need to connect to the modem
what "basic sky router" is it?
If you look at the label on it, it should have a model.
that'll tell us if its a modem, if its a modem/router combo device, or what it is exactly.
If its a combo device, then you could setup the R7000 in bridge more or even use it as a repeater