Lee Johnson has spent the summer scoping potential signings - and expects a steady 'trickle' of arrivals affter Sunderland return for pre-season training next week.
The Black Cats will assemble at the Academy of Light on Monday, but Johnson will be short on numbers with seven players released at the end of last season and no replacements brought in as yet.
But Johnson has been working with sporting director Kristjaan Speakman, head of recruitment Stewart Harvey, and data expert James Young to line up the men he believes can help Sunderland win promotion.
"I would love to tell you I've had a summer break, but my summer has consisted of being stuck in watching [online scouting tool] Wyscout and looking at players and recruitment data, holding Zooms with potential players that we might bring in, with our current players, and with ones who are out of contract that we want to renew," Johnson told the club's official website.
"I haven't watched a minute of the Euros, which could be a good thing or a bad thing, but I have enjoyed the break because I have been part of the process to determine what we need, and how we are going to do it in terms of matching the data with the eye and the football nous.
"That's been an enjoyable process but it will be even more enjoyable when we start getting players through the door and can start working with them, building a new XI and a new squad to hopefully be able to implement what we are trying to achieve.
"There's not much I can do [on Monday] apart from have a five-a-side, I think, given the number of players we have got coming back at the moment!
"But I do expect a trickle of new players, and hopefully players re-signing where possible."
While Sunderland are yet to make their first signing, the same can be said about most clubs in League One at this stage - with only a handful making early moves.
Johnson expects that to change once teams return for pre-season training, and he believes that the coming season will be the most competitive ever in League One as clubs such as Ipswich, Sheffield Wednesday, Portsmouth, Oxford, Charlton, and Lincoln eye promotion.
Of the quiet transfer window so far, he said: "A lot of it is the market and what the market constitutes.
"We are hopefully now at the back end of the pandemic, but a lot of Championship clubs are the ones that have been hit the most.
"Funnily enough, a lot of League One clubs seem to be going for it this year and there's a fair bit of money flying about in League One, so that will be interesting and it will probably be more competitive than it has ever been.
"At the same time, our challenge is to go and recruit to win the league, it is as simple as that.
"These are the sleepless nights that you have, but they are also full of hope and also that football IQ that allows you to streamline financially but get the best team possible for that.
"We're working really hard, there are a lot of new people at the football club with the sporting director Kristjaan, James in data, Stewart in recruitment, the coaches, and we all have to get to know each other extremely quickly.
"I have really enjoyed being a part of building that backstory over the summer, but it hasn't left me with a holiday!"
