Five new players have arrived at Villa Park this summer with the high-profile capture of John Terry being followed by the signings of Ahmed Elmohamady, Glenn Whelan, Chris Samba and goalkeeper Sam Johnstone, the latter joining on loan from Manchester United.
Bruce would ideally like to add a couple more, including a striker, as he looks to build a squad capable of winning promotion from the Championship.
But the manager has acknowledged any incomings must be balanced by outgoings, as Villa look to stay within the boundaries of Financial Fair Play.
Jordan Veretout, Carlos Sanchez and Nathan Baker have all left the club in permanent deals, while Villa have also rejected a £1.5million bid from Reading for utility man Leandro Bacuna.
Bruce explained: “As I have said many times we are on the cusp of Financial Fair Play and we still need to get more out really.
“Of course I am like any other manager and would love a huge amount of money to spend, of course I would.
“But at the moment I would like to box a bit clever. The one thing you can’t do is be on the thick end of Financial Fair Play. I am aware of that.
“There are one or two bits bubbling along. My job is always to knock on the door and I will repeatedly knock on the door because we can never be satisfied.
“If we added one or two to what we have already got I would be really, really pleased with what we have done.”
Villa rounded off their pre-season schedule with a 0-0 draw at home to Premier League Watford.
They kick-off their Championship campaign next Saturday when Bruce’s former club Hull visit Villa Park.
Bruce added: “The same old problem arose against Watford where we have had some unbelievable chances and missed them.
“We can’t, as I have said repeatedly, keep relying on Kodjia. Sometimes we are going to be without him.
“We have good players. Gabby (Agbonlahor) is looking remarkably good. Scotty Hogan has looked good. We are hoping it is their season.
“We have got goals from midfield I do believe in (Henri) Lansbury and (Jack) Grealish. All in all the balance of the squad looks good.”