Exeter City boss Gary Caldwell says any money from the sale of Sam Nombe will not be spent in this transfer window.
The 24-year-old has joined Rotherham, for a fee reportedly in the region of £1m, two years into a three-year deal.
Caldwell says he is focused on bringing in a new striker to replace the former Milton Keynes Dons forward, who scored 27 goals in 85 games for City.
"We agreed a budget at the beginning of the season, we're trying to stick as much as we can to that," Caldwell said.
"I think this football club, more than most, understands the finances and how we look after them is really important for the long-term future of this football club, so we won't be reinvesting that money in the team in this window.
"We have a target we believe will be a fantastic number nine, but I think the money we've brought in this window is for the long-term future and the long-term planning of how we see the team moving forwards in League One for years to come, and hopefully even higher."
Fan-owned Exeter are set to bring in well in excess of £2m in fees over this summer window after Josh Key and Archie Collins moved to Swansea City and Peterborough United respectively for six-figure fees, while the club will get about £1m from a sell-on clause in the deal that saw Ethan Ampadu join Leeds from Chelsea.
Caldwell is still looking to strengthen his squad in other areas, but says after an acceptable offer was made for Nombe the best decision was to allow him to leave.
"I believe it is in the interests of the football club, and that from me is my job to not only get the best team on the park, but make good sound football decisions for the long-term future of the football club," he told BBC Sport.
"I believe we have made the right decision, but it's also important we put a team on the park that can be successful this season and beyond as well, which we're trying to do."
Exeter will be 'underdogs' in Luton tie
Meanwhile Exeter's reward for making the third round of the Carabao Cup for the first time since 1989 is a home tie against Premier League side Luton Town.
The Grecians progressed after a penalty shootout win over Stevenage on Tuesday - they have failed to beat Luton in their past seven encounters, in the FA Cup and when the two sides were in League Two.
"I'm delighted with a home draw, I think when I saw our number come out - to be at home it was great, and then to get a Premier League club is great," added Caldwell.
"It's a Premier League team, it's a team that has had a fantastic journey in the last 10 or 11 years to get from non-league to the Premier League.
"We are massive underdogs in this game. We will treat them with the same respect we treated Crawley and Stevenage and we'll give everything we can to win, but we're massive underdogs."