The Black Cats are among the leading contenders, alongside the Millers, to be promoted with a number of bookmakers already making Paul Warne’s men odds-on favourites to go up.
Given the manner of their win over Sunderland - which extended their unbeaten league run to nine games - it is little surprise that Wiles feels that their divisional rivals need to start fearing Rotherham more.
The midfielder also dismissed the notion that the New York Stadium side are simply a big, physical side who do not play attractive football.
“It is a warning to the league itself. We are a good few games unbeaten at the moment,” he said.
“Teams need to start fearing us a little bit because we are not just this physical team, we can actually play.
“We are a nightmare, we press people and we are ugly at times but that gets us results.
“If that gets us promoted at the end of the season then everybody will take that.”
The win saw Rotherham leapfrog the Black Cats into fourth place as Michael Smith and Freddie Ladapo both netted two goals each while a header from Michael Ihiekwe completed the scoring for Rotherham.
Ross Stewart got Sunderland’s only goal as the visitors also had Aidan McGeady sent off early in the second half with the Millers leading 3-1.
Rotherham United: Vickers, Harding, Barlaser, Wiles, Ladapo, Ogbene (Sadlier 75), Ferguson (Miller 75), Rathbone, Ihiekwe, Edmonds-Green, Smith (Kayode 75). Unused subs: Johansson, Wood, Bola, Odoffin.
Sunderland: Hoffmann, Flanagan, Doyle, Dajaku (Evans 59), Embleton (Gooch 46), O’Nien (Wright 46), Stewart, Winchester, Cirkin, Neil, McGeady. Unused subs: Burge, Alves, O’Brien, Wearne.
Referee: D Rock (Hertfordshire).