Anthony Chapman of the Express claims the Red Devils will set aside £180 million for transfers in the pre-season window, with German internationals Mats Hummels and Benedikt Howedes also targets to add to LvG's fragile defence.
Ronaldo has been linked with a return to United on countless occasions, as reported by Jamie Jackson of The Guardian in 2014, with Angel Di Maria also professing CR7 convinced him to join the Old Trafford giants.
Speaking to the club's Inside United magazine, per Joe Strange of the MailOnline, ADM said Ronaldo had an influence on his £60 million British transfer record move to United after the Portugal maestro sung the praises of the Red Devils:
Before we knew I was coming to Manchester for sure, he (Ronaldo) told me it was a massive club and that I would be very happy here and it would be good for me.
At that time, we didn't know for sure that I was coming or not, so we didn't go into great detail, but what he did say helped me greatly to make my decision.
And former United coach Mike Phelan also recently claimed Ronaldo would listen to offers from his former club if the deal was right for all concerned, per David Wright of the Express.
However, Phelan added the player currently appears happy with his role at Real Madrid and is likely to remain in his Spanish surroundings:
Ronaldo loved his time at Manchester United and, if Manchester United were interested in him again, then he would listen to that because part of his career has come through Man United.
But listen, he is where he is because of him being Ronaldo and, at the moment, Madrid are successful so I can't see why he would think about coming back to Manchester United now.
Arturo Vidal is also back on United's radar, with Chapman saying Juventus have warned the midfielder they are now prepared to sell him unless his performances improve for the Old Lady.
In a separate article for the Express, Chapman says Juve now see Paul Pogba as their central midfield general and will sacrifice Vidal if the conditions are right in the summer.
Vidal has only managed to accumulate 10 starts in Serie A this season, per WhoScored.com, but has still recorded five goals to his name during the current campaign.
But his knee problems have been an ongoing soap opera, and it is questionable whether United will take a risk on the Chilean superstar.
Ronaldo and Vidal are indeed fantasy signings for the Reds, but only a few months ago, the captures of Di Maria and Radamel Falcao would have been just as unlikely.
United mean business, and the fact they are comfortably in the top four will enthuse them to set up a number of huge deals in the summer.
Van Gaal must look at genuine, world-class talent, and CR7, Vidal and Hummels certainly fall into the bracket.
And with Marco Reus close to agreeing to a transfer to Madrid, per Chisanga Malata of the Daily Star, there could well be a chance Los Blancos will cash in on Ronaldo if the offer is an exceptional one.
After his performance in the Champions League, it seemed unbelievable that Madrid would sell Di Maria—and it is this level of unpredictability that makes a Ronaldo deal more of a possibility than it really should be.