The Tigers progressed to the fourth round of the league cup thanks to Nick Proschwitz's 59th minute goal but Bruce said the performance left a little to be desired.
"It was a comfortable evening for us but it was, if I'm being honest, like watching paint dry," he said.
"There was no real cohesion to us, it was both managers throwing 11 bodies on the pitch really.
"Once you lose that cohesion there was no real tempo to it because of what it was. It was more like a friendly that a cup tie.
"But that's what the early rounds of the cup have turned into now; it's a shame but there you have it."