New boss Louis van Gaal has already splashed £60m to land Ander Herrera and Luke Shaw, but is set to open the Red Devils’ owners’ chequebook with some regularity in the coming weeks.
United finished last season in eighth, which has prompted talk that their backers are willing to spend massive amounts to ensure that Champions League football is secured this time around.
LVG is ready to take advantage of this, earmarking di Maria and Vidal as his next arrivals.
The former is available from Real Madrid for around £38m, with Los Blancos keen to sell as they step up their own transfer plans.
The classy winger is currently away at the World Cup, and is seen as the ideal man to provide Robin van Persie and Wayne Rooney with the ammunition they need.
Vidal is also wanted, with van Gaal prepared to pay up to £50m.
The Chilean is widely considered to be the best box-to-box player on the planet, and has been in terrific form for Juventus in recent years.