Bruce says seven games worth of analysis, including a defeat at Norwich and losing 5-0 at Leicester last time out, have forced his usual formula to be ripped up.
He said: “In the Premier League, everywhere you look, you've got to be big and physical and have the ability to run. Unfortunately that is one thing here now, from the back, to my midfield, we haven't got.
“Ultimately, until we've got that, we're going to have to play in a certain way and the identity will be to sit deep and play on the counter-attack because that is the only way we can play.
“I quickly worked out at Norwich that we didn't have the players with the capability to play the way I'd envisaged. Norwich played through us repeatedly.
“We get the statistics from every game and they tell the story. Compared to everyone else, and especially in midfield and defensive, we register in a certain way."