Tottenham chairman Daniel Levy says they've paid for poor past signings.
Among their additions, they paid 54m for Tanguy Ndombl in the summer of 2019 and 60m for Richarlison ahead of this season.
Levy admitted to Sky Sports: "Our recruitment must be of the highest class.
"We have made mistakes in recent years and mistakes affect the financial and sporting aspects in the years to come.
"We have taken steps to improve this area and we believe the recent transfer windows reflect this."