Bruce was speaking after seeing the Tigers edge through to the second round of the Capital One Cup with a 7-6 penalty shoot-out win against Rotherham United at the KC Stadium, which followed a 1-1 draw after 120 minutes of open play.
Asked how much of an improvement there needs to be, Bruce said: “A lot. As I’ve said before, the big disappointment in pre-season has been that too many players have picked up niggly injuries and missed two or three weeks. At this stage, it’s catch-up time but we’ll be okay.
“On Saturday I thought we started particularly well and had two or three opportunities. I was very pleased with how we played in the first half and we should have been in front. But I’ve come to learn very quickly that our Achilles heel is not taking the chances and not scoring enough goals.
“We can’t go into a game like on Saturday and miss seven or eight chances, but overall we got through and we’re in the next round of the cup.
“A lot of people needed that game. Matty Fryatt has missed three weeks of pre-season and you could see him tiring as the game went on, Abdoulaye Faye and Liam Rosenior also. We needed the run-out, we got through and now we can look forward to the start of the league season next week.
“What I learned from Saturday is that there is still a lot of work to be done.”
Despite those sentiments, there were plenty of positives for Bruce.
“I thought Cameron Stewart and James Chester were terrific and Joe Dudgeon did particularly well, he gives you everything he’s got.
“The penalties were also very good and we’re through to the next round.”