The Tigers travel to Belgium on Thursday knowing that they are just two legs away from qualifying for the group stage of the competition.
However, with Lokeren currently occupying sixth place in their domestic league, Bruce is confident that the home side will give his players a tough match.
"Lokeren are a very, very good side from what I've seen of them and as we know, Belgium is producing some very good players," he told the club's official website.
"It will be a difficult game for us. As I've said, I'll be changing my team around and giving the players who got us into Europe the chance to play in Europe."
Hull got their Premier League campaign off to a winning start last Saturday with a 1-0 victory at Queens Park Rangers.