Bruce has already vowed to make wholesale changes for the two-legged clash, which gets under way with the first leg in Belgium on Thursday, and he intends to adopt the policy as long as Hull are involved in the competition.
Despite looking set to field a weakened XI, Bruce, who led his side to a 1-0 win at QPR in their Premier League opener on Saturday, warned against taking the Belgian outfit lightly.
"Lokeren are a very good side," he said. "They're a good team from what I've seen and Belgium is now producing some really good players.
"It's going to be a difficult game for us.
"As I've said, I'm going to change all my team round and give everybody a game to give the players who have got us into Europe the chance to play in Europe.
"I think that's what gives us the spirit that they play with at the moment. They're all going to get their chance.
"I had to leave people off the bench [on Saturday] - George Boyd in particular - who've done wonders for me, so we'll be okay."
Bruce also expressed his relief that striker Hamdi Harbaoui had left the Belgian club for Qatar SC last month.
