United were already known to be targeting the pair, who would have a likely combined cost in the region of £100m, in an attempt to strengthen key positions ahead of next season. But a report from The Times has now revealed the urgent timescale behind the deals.
Talks with Spurs over 29-year-old Alderweireld were reported to have begun earlier this week, although the apparent opening response from Tottenham chairman Daniel Levy was to slap a £75m price tag on the Belgium international.
The Times notes that even a reduction on that figure could still top £50m, despite Alderweireld being available for just £25m next summer when a release clause becomes active.
It is said that United have at least 'gained encouragement' after Spurs 'privately accepted' that they would allow Alderweireld to join a rival Premier League club, whereas before they were only prepared to sell him to a foreign buyer.
Securing the Alderweireld deal is likely to be a battle of intense negotiations, but it is thought that United will have a much easier time landing emerging Brazil star Fred. An Italian report claimed that a £44m deal has been agreed, though The Times suggests it will be closer to £52m.
The hope is that the 25-year-old will be able undergo a medical next week as the Brazil squad will be in the country ahead of a World Cup warm up friendly against Croatia at Anfield.