Bruce invested heavily in his engine room this summer, paying out a total of £11million to recruit England Under-21 international Cattermole from former club Wigan and Albania skipper Cana from Marseille.
He is already reaping the rewards with the pair having established a combative central partnership which has helped to lay the foundation for a positive start to the season.
But both men were booked in last Saturday's 4-1 victory over Hull, taking 26-year-old Cana's tally to three and 21-year-old Cattermole's to two in just five league games.
Bruce knows that a continuation of that record will inevitably lead to suspension problems but he has no intention of taking the aggression out of their game.
He said: "I am not going to, it's as simple as that. They are not deliberately going out to maim somebody, that's for sure, but the amount of tackles they both try to make, they are going to make one too many or mistime one. But if we can just calm them down a little bit, then obviously we will do."