Ole Gunnar Solskjaer is keen to recruit a new left-back before the end of the transfer window and Reguilon, along with Porto’s Alex Telles, have both been linked with moves to Old Trafford.
However, Marca report that United have intensified their negotiations with Real Madrid over a deal for Reguilon and a move is now believed to be close.
The report claims that United will pay around €25 million (£23m) to sign the 23-year-old but Madrid are still insisting on having an option which will allow them to re-sign the defender within two seasons.
Marca also report that United’s hierarchy have already stressed to Reguilon’s new agent, Kia Joorabchian, that the defender will be a key part of their plans.
Reguilon is currently recovering at Madrid’s training complex after suffering an ankle injury during Spain’s win over Ukraine earlier this month.
The defender impressed during his loan spell with Sevilla last season and helped the Spanish club win the Europa League, but he is not in Zinedine Zidane’s plans for the upcoming campaign because Marcelo and Ferland Mendy are his two options at left-back.
Sevilla are also keen on re-signing Reguilon, while Tottenham have also expressed an interest.
Alex Telles’ contract with Porto is due to expire at the end of the season and the Portuguese club do not want the 27-year-old to leave on a free transfer.