The League Two side gave Blues a fright with their second half performance and Bruce complimented Leroy Roseniors side after the game at Plainmoor
"I thought we were ok in the first half but in the second half give full credit to Torquay because they played well and we've got off lightly to be perfectly honest," Bruce said.
"If we play like we did in the second half come the replay then we'll make it a difficult night for ourselves. We've got to go and play and take part in the game because in the second half today we just didn't.
"We were waiting for something to happen and the longer the game went on then Torquay became more confident, their crowd got behind them and made it a difficult afternoon for us.
"We're relieved to still be in the hat. We've got away with it today because Torquay played very well in the second half."