A day after Manchester United were linked with Reguilon, Tottenham have stepped in with an official bid and reached an agreement with Real Madrid worth €30 million, according to The Guardian's Fabrizio Romano.
Manchester United were preparing a formal offer for the 23-year-old earlier this week but were unwilling to match Real Madrid's asking price and proposal to include a buy-back clause in a deal.
However, Tottenham have accepted Real Madrid's €30-million valuation and agree to buy-back and pre-emption clauses, Romano adds. An agreement over the latter proposals allows the Spanish side to match any future bids that Spurs accept and bring Reguilon back to the Santiago Bernabeu.
Spurs are also negotiating with Reguilon's representatives over a contract, Romano reports.
Tottenham have made progress, but the deal remains incomplete.
Manchester United could re-enter the discussion, with reports that Reguilon was hoping to make the switch to Old Trafford, but the Red Devils would have to accept Madrid's terms now that Spurs have an agreement.
Reguilon made 38 appearances in all competitions while on loan at Sevilla last season. He was also named in Sevilla's starting team for their Europa League final win last month.