Keates, who is keen to add stability to the squad ahead of the opening game of the season, insisted that Dunn has not been signed to make up the numbers, and expects the stopper, who also played for the likes of Northampton Town, Coventry City, Yeovil Town and Cambridge United before joining Wrexham, to push Liam Roberts for the coveted number 1 spot.
Speaking via the Express & Star, Dean said; "Robbo knows how I feel about him and how the football club feels about him. I hold him in high regard, he was outstanding last season. He is one of the main reasons we kept our League One status.
"He can only take confidence from the way he performed last season. But Dunny will come in and help him. We have also added Michael Oakes as well. They will both help Robbo because they are both vastly experienced. Robbo has got the opportunity now to mature, play games and push himself to be number one for his home-town club. And Dunny will come in and help him but also push him really hard."
The gaffer then went on to confirm that the club's new arrival had agreed terms on a deal a few weeks ago but had to wait for everything to be finalised following Mark Gillespie's move to Motherwell, he continued; "I know Dunny well, he is experienced and he will bring something to the changing room. He is a big lad at six-foot-five. And he kept a lot of clean sheets in the last 18 months I worked with him.
"I’m delighted to get him. It’s something that has been done for about three weeks. It was a case of getting everything finalised with Gilly’s move to Motherwell. I was looking at my options and I knew Dunny was available. I know how he conducts himself and how he operates. He comes into the squad and makes it very competitive for the number one jersey."