Agreed, call them rca inputs. Phono is a specific application on an avr, as it will include an appropriate gain stage and RIAA eq for generally moving magnet (MM) type cartridges on turntables. In any case the Denon 770 doesn't have a phono input, just two analog rca inputs (media player and cbl/sat).
With modern avrs you may need to look at the input assignment menu of the avr for the analog rca inputs you're trying to use, they generally start with an assumption of digital input for automatic assignment. See page 173 of the pdf manual for the avr.
You do have toslink inputs, but they are of the optical variety. I imagine there are converters from digital coax to optical to accommodate your old player, tho I would just use the available analog out from your player to analog inputs on the avr.