Derby signed 30-year-old centre-back Nelson on a free transfer from Blackpool to strengthen their defence.
Cashin and Nelson have partnered each other in seven of the eight games in the league for Derby so far this season and have kept three clean sheets.
The Derby star stated that new boy Nelson is very good at communicating and revealed that they both help each other on and off the field.
Cashin also revealed that during the game they both tell each other what to do and believe that good communication on the pitch is important to building a good partnership.
“He is very good at communicating, and he is very good”, Cashin told RamsTV.
“I often ask for advice and stuff and I think it goes both ways, obviously.
“I tell him what I want from him in a game and he will do the same to me and I think that is the important thing about building a good bond and good partnership together.”
Derby are currently in ninth place in the League One table with 13 points from eight games.
