Jose Mourinho conceded Tottenham cannot compete with the spending power of Premier League rivals like Chelsea and Manchester United.
Spurs broke their transfer record last July to spend £55 million ($68m) on Tanguy Ndombele from Lyon, while the acquisitions of Giovani Lo Celso, Steven Bergwijn and Ryan Sessegnon in the past two windows took their outlay to well above £100m ($124m).
However, Mourinho does not anticipate more big spending when the window reopens, despite seeing Chelsea this week agree a £47.5m ($59m) deal to acquire Timo Werner in July having already reached terms with Ajax's Hakim Ziyech.
"Every club has its own situation and philosophy and approach," Mourinho told a news conference.
"I'm not expecting to be in position of great spending. I'm expecting my club to be very balanced and honest in that kind of approach.
"We know that we are going to be in the same league, in the same world, as clubs that are going to do completely different to us.
"We have examples already of clubs investing, making important movements in the market and we are still nine matches from the end of the season.
"But we are always going to be very balanced as Tottenham normally is. Would I expect us not to do anything and stay with exactly the same squad? My answer is no. I would expect us to do some little important things, if we do them, and improve in two, three positions.
"I am completely open to the changes, completely supportive of the owners and let's go for it. In this moment, I'm not even thinking about that because I'm focused on these nine matches."
Spurs resume their Premier League campaign and their quest to secure a top-four finish against Manchester United, another of Mourinho's former clubs, on Friday.
United were on a good run prior to the break, having been boosted by the arrival of Mourinho's fellow countryman Bruno Fernandes in January.
Mourinho, who was appointed Tottenham manager in November, claimed to be unaware of whether his club were keen on Fernandes, but he again stressed Spurs' rivals have greater resources.
"I don't know if Tottenham was in on the Fernandes situation, I cannot confirm or deny," he added.
"But it's obvious for us that there is a certain level of options that they are not for us and we have to admit that, but that's a normal situation.
"United bought Fernandes, Chelsea bought Werner and Ziyech - they can do what they want, it isn't our problem. We focus on ourselves. We are going to improve our squad, in the way we can do it. No problem."
Tottenham, currently eighth in the table, are seven points behind fourth-placed Chelsea.