Penney, who officially took over at Boundary Park last month following his resignation from Darlington, believes Norwich, Leeds, Southampton and Charlton will be among their main challengers in League One.
He told the Manchester Evening News: "It's going to be a tough division - especially with the teams that have come down, they are big teams.
"With Leeds not going up, you've got four massive teams. There is a massive supporter base in Norwich and Southampton and Charlton were in the Premier League not so long ago.
"I also know for a fact that there are few teams really going for it financially and having a real good crack.
"If you've got the biggest budget you should be at the top. But there is always somebody, who goes against the grain, that ends up having a good season through good players, luck with suspensions and luck with injuries and hopefully they can come out near the top."