"Teams will go there and underestimate Rotherham at their peril and I suspect some already have," Smith told the club's official website.
"Who would have said they would go to Millwall on the opening day and win 6-0?
"Even after that many said it was a freak result but they warrant their position in the top five on subsequent results.
"They don't possess instantly recognisable names but they are a team of fighters.
"If any proof was needed then you only have to look at Tuesday night where they trailed 3-1 with about 15 minutes to go and eventually won after extra time.
"They have surprised a few by the start they have made but not me. They have a manager in Ronnie Moore who understands the club.
"Some are waiting for them to slip up somewhere but Rotherham have proved people wrong so far and they will do so again."