Town boss Kieran McKenna says the Blues will continue to look for additions in the final couple of weeks of the transfer window.
The squad has been significantly strengthened with the loan addition of Kalvin Phillips from Manchester City and the permanent signing of Sammie Szmodics from Blackburn Rovers earlier today.
Sweden international Jens Cajuste has been spotted in Suffolk ahead of undergoing a medical prior to the confirmation of his season-long loan from Napoli, a move which will reportedly cost the Blues €1.5 million (£1.3 million) with a mandatory €12 million (£10.2 million) buy-out should Town stay up.
But Town had six of their new signings in the door ahead of or during pre-season, which pleased McKenna.
"It was important,” he reflected. "The reality is that we would have liked to have had more. It’s been a challenging summer, that’s the reality.
"As a double-promoted team coming into the Premier League, it’s been a challenge. We’ve worked so hard on our recruitment. We feel like we’re making some progress.
"Of course, adding two players today is super and hopefully they can possibly have some involvement tomorrow and for the weeks ahead, but, of course, we would have liked to have had everybody in for the first day of pre-season.
"You make the steps that we make, you get promoted from the Championship, you have loan players go back to their parent clubs, some players’ contracts expire. We had some injuries in pre-season, the reality is that we’ve been working with a smaller group than we would have wanted.
"We would have wanted to have had our whole squad in for the pre-season, but that’s not always the reality of football.
"I think what is important and what is positive is that we’ve tried to stick to our principles in terms of the type of players, the type of people that we want to recruit.
"In general, when we’ve spent significant transfer fees, we’ve tried to do it on players that we think have development value for the football club that can still develop over the next years with the football club, that can improve us as a team in the medium and longer term and also have an asset value for the football club.
"We’ve tried to spend our money in the right way, while maintaining the balance of bringing in some senior players, bringing in players who can have an immediate impact and our playing at close to their best levels already.
"We’ve tried to stick to our principles, we’ve tried to bring the right players in, the right people. We’ve been patient. If we feel like the right signing isn’t there, we’d rather make an addition today or in two weeks’ time than make an addition at the start of June or at the start of July that wouldn’t be right for the football club in the medium and longer term.
"It’s been a busy window, there’s no doubt about it, it’s been a challenging window. We’re happy with the players that we’ve added. I think all the players we’ve added add to us, both on and off the pitch.
"But we know that we need to improve more. We know that we need to improve the depth of the squad first and foremost in terms of the numbers, that still needs to improve and we know that we will still look to add different qualities over the next couple of weeks, and that means that we’re going to be building and improving a squad as the season’s already started.
"But that’s the reality of it for a team that’s in our position and that’s something that we’ll look to do and another reason why I think that we will hopefully start really fast, but also that I think we’ll have great scope to improve over the next few weeks and next few months.”