With Luke Shaw set to be sidelined for at least two months, after picking up a muscular injury, Erik ten Hag is low on available left-backs. Diogo Dalot deputised in another calamitous United performance on Saturday, as Nottingham Forest were beaten 3-2 after holding a two-goal lead.
Reguilon has not played for Tottenham since April 2022 and spent a frustrating spell on loan at Atletico Madrid last season. United explored signing the Spaniard in 2020, but eventually opted against it.
Cucurella is also out of favour at his club, despite joining from Brighton in a deal worth a staggering £62million less than a year ago. Manager Mauricio Pochettino prefers Ben Chilwell at left wing-back.
Manchester Evening News report that both Spaniards are of interest at United as the club look to sign a specialist left-back, most likely on loan.
It is claimed Reguilon's wage demands could be out of United's reach.
Ten Hag has confirmed interest in signing a left-back, telling reporters: "It can be [that United sign a left-back]. I think we always have to anticipate on situations. If there are opportunities then yes, but it has to be the right player otherwise we have to deal with the current squad.
"We went through the scenarios before the season and if it happened, we have the solution."