Alex Telles last month made a permanent switch to Al-Nassr and Brandon Williams’ loan move to Ipswich was announced the day before Shaw’s extended absence became public.
United have scoured the market for a left-back since then, with Reguilon looking the most likely option to join on loan as Friday’s deadline looms.
The 26-year-old was linked with a move to Old Trafford three years ago and spent last season on loan at Atletico Madrid.
Spurs are understood to have given Reguilon permission to travel to Manchester for a medical, with an agreement close. Chelsea’s Marc Cucurella was another option they looked at.
Negotiations continue for the Morocco international – who worked with Ten Hag at Utrecht – as the Red Devils look to bring in the 27-year-old while balancing financial fair play requirements.
Marc Jurado could make a permanent move back to Spain, while young striker Charlie McNeil should complete a loan switch to Stevenage.