Bruce managed to guide Sunderland to 13th position last season.
He told the Sunderland Echo: “I think it will be very difficult for us to break into the top group, next season, though that has got to be the aim.
“They’re some distance ahead of the rest both in terms of resources and of being established in the Premier League.
“They’re teams that are either super rich or have benefited from the financial success that finishing high up the division regularly will bring.”
Bruce continued: “When you look at the top eight, arguably the most vulnerable of those teams is Everton but they’ve had the advantage of being in the Premier League since it started.
“Being in the league year after year allows you to build and be established, it makes it easier to recruit players.
“Everton haven’t been awash with the cash that the teams above them have but David Moyes is a top manager who has consolidated wisely and will be very hard to catch up next season.”
He added: “The first thing we’ve got to do is eradicate the awful performance that we still have in us away from home.
“We’ve got to eradicate this horrible inconsistency where we can be superb at home and very, very poor away.
“Overall, we improved towards the end of the season – statistics tell us that more than anything else – but the challenge next season will be improving away from home.”
