After a very quiet January transfer window at Old Trafford. Manchester United fans can look forward to what looks likely to be a busy summer window.

Indeed, the Red Devils are surely set for a major overhaul. While there is clearly talent coursing through the club's ranks, the loss to Paris Saint-Germain in the Champions League showed just how far off United are when it comes to battling the real elite of the footballing world.

Though no one is quite sure of the managerial situation at the Theatre of Dreams, investments clearly need to be made if the glory days of the Sir Alex Ferguson era are to return at long last.

Here, we look at a couple of faces who can be brought in by the club to try and push them back to the summit of Premier League football. 

Kalidou Koulibaly 

Koulibaly has been heavily linked with a move to Manchester United for some time now, and it could be argued that if United don't act fast in the summer, the highly rated defender could end up signing elsewhere.

The Senegalese centre-back has proven to be the heart of a very strong Napoli defence this season. Starting in every game possible, missing two games due to suspension, the 27-year-old has proven defensively solid, helping the Italian giants to keep thirteen clean sheets in the Serie A this season.

He has been integral to their solid form of late, currently keeping five consecutive clean sheets. The £63 million valuation from Transfermarkt, won't faze Manchester United at all, as in the past we have seen they are not afraid to spend in such a market.

Jadon Sancho

Jadon Sancho is one of the most talked about wonderkids coming out of the Bundesliga this season. Indeed, after providing 8 goals and a staggering 12 assists in the league it is clear to see why everyone has their eye on the young star.

With Ole Gunnar Solksjaer looking likely to be given the job on a permanent basis and already looking at the youthful side of United, it is clear to see why the purchase of Jadon Sancho would fit perfectly.

Being an England international, the young winger has already struck relationships with the likes of Rashford and Lingard during England duties, having picked up three caps with the Three Lions.

The signing of Sancho would have a warm welcome from the fans, as they can only dream of adding more pace and skill in an already rapid front three.