Man United are reportedly keen on signing a former defender despite letting him go back in January.
United are looking to bolster their defensive reinforcements this summer after first-team coach Erik ten Hag signed a new one-year contract extension at Old Trafford.
They've already expressed interest in Bayern Munich defender Matthijs de Ligt and are reportedly ready to offer the Dutchman a five-year contract if they can strike a deal for £42m including add-ons.
However, even with a move for de Ligt lined up, United are reportedly interested in one of their former defenders - who only left the club six months ago.
According to the Metro, United want to sign Tottenham full-back Sergio Reguilon on a permanent deal during the summer.
Manchester United are reportedly keen on re-signing one of their former defenders
Sergio Reguilon spent last season on loan at United from Premier League rivals Tottenham
The Spaniard spent the first-half of last season on loan at Old Trafford before later joining Brentford for the remainder of the campaign.
Reguilon had been brought in due to the left-back injury crisis that United had endured - with both Luke Shaw and Tyrell Malacia sidelined for lengthy periods.
The 27-year-old made 12 appearances in total for the Red Devils and managed to impress with his performances down the left-flank.
Reguilon's deal at parent club Tottenham is set to expire next year and, as a result, Spurs are keen to cash in on him during the summer transfer window.
Meanwhile, United are already making movements in the window as they close in on the signing of Bayern Munich's De Ligt.
United want De Ligt to play on the right side of central defence and have not given up hope of signing Branthwaite to play alongside him on the left if they can sell players to raise the funds.
United have reportedly offered Bayern Munich's Matthijs de Ligt a five-year deal at the club
Erik ten Hag is believed to have earmarked De Ligt as a top target in United's defensive rebuild
An opening bid of £38m plus £5m in add-ons was rejected by Everton who don’t want to sell the 22-year-old but could be forced to listen to offers in the region of £70m.
United are unlikely to go that high but are weighing up an improved offer for Branthwaite who is understood to have grown increasingly agitated over the lack of movement in negotiations.
However, United are expected to step up their transfer business now Dan Ashworth has been cleared to start work as sporting director as they look to bring in a striker and defensive midfielder as well.