In what could well turn out to be the most expensive and highest-profile transfer of the summer window, Manchester United star Angel Di Maria is set to join Paris St. Germain for £44.4million - according to The Daily Mail.

There's an obvious disappointment amongst the Red Devils fan base in seeing such a talented player quit the club after just one season, especially having arrived at Old Trafford last summer for a Premier League record transfer fee.

But the Carrington outfit can't ponder the past now and the good news is that they've got £44.4million (plus whatever Louis van Gaal has left in the bank) to sign an adequate replacement.

But who could realistically bring that same level of 'wow factor' to Old Trafford? Who has the talent to match Di Maria's abundance of ability?

We at Football Fancast have whittled down FIVE choices from across Europe for the Red Devils to choose from. Which of these should be signed as Di Maria's direct replacement?

PEDRO

Manchester United's interest in Pedro is no great secret, with the volume of reports linking the Barcelona winger-forward with an Old Trafford switch seemingly increasing by the day, and admittedly, it's hard to look past the 27 year-old as the ideal replacement for Angel Di Maria.

Indeed, Pedro has done it and won it all throughout his tenures with the Catalans and the Spanish national team, namely lifting five La Liga titles, three Champions League titles, the 2010 World Cup and the 2012 European Championship.

Alexis Sanchez has added a whole new dynamic to the Premier League title race since signing for Arsenal last summer and his former team-mate has the potential to do the same, blessed with a similar blend of trickery, industry, pace and netting prowess.

Most prevalent is the 51-cap international's work rate both with and without the ball - which should make him a huge hit in the English top flight.

Furthermore, Pedro's £22million release clause offers fantastic value for money; essentially, a world-class player without a world-class price-tag. But are there better options on the market this summer?

ANTOINE GRIEZMANN

Something tells me 'multifunctional footballer' enthusiast Louis van Gaal will be particularly fond of Atletico Madrid's Antoine Griezmann.

The France international gained notoriety as Real Sociedad's hard-working, free-scoring left winger, bagging 52 goals in 201 appearances - including back-to-back double figure campaigns in La Liga - and playing a talismanic role in the club's rise from the second tier to the Champions League in the space of four seasons.

But since moving to Atletico last summer, the 24 year-old has transformed himself into a potent centre-forward - netting 25 goals across all competitions for his debut campaign.

Much like Pedro, Griezmann possesses the industry and tenacity to be a real success in the Premier League - which is why he's flourished under Diego Simeone's attritional philosophy. But he's also a very technical player with good pace and fantastic movement in the final third, alongside his aforementioned versatility.

The good news is that the 5 foot 9 attacker's Mattress Makers' contract includes a release clause, meaning United don't have to spend the rest of the transfer window convincing the club to sell. The bad news, however, is that it's set at a rather steep £43.5million.

NICOLAS GAITAN

As a fellow winger of considerable Albicelestial ability, there are plenty of similarities between Angel Di Maria and countryman Nicolas Gaitan.

The 27 year-old is perhaps a little less dynamic than Di Maria, lacking his penetrative pace, all-round energy and netting prowess, with just 30 goals in 216 appearances for the Primeira Liga outfit.

But Benfica signed Gaitan as the departing Manchester United star's replacement in 2010 (as he headed for Real Madrid) and the two are of a similar mould; both playmaking varieties of wide player, with clinical crossing and the ability to play in more central roles when required.

Gaitan has been linked with a move to the Premier League - particularly Manchester United and Chelsea - for much of his Benfica career, and the rumours have emerged once again this summer.

The Metro claim the Red Devils are willing to use Javier Hernandez as a makeweight to bring the nine-cap Argentine to Old Trafford, which certainly wouldn't be the worst of deals.

But Gaitan is now the only true standout star in Benfica's starting Xi - so it will take a considerable offer to convince them to sell.

MARCO REUS

Marco Reus signed a new contract with Borussia Dortmund only last February, eradicating his previous ridiculously low £25million release clause. But it remains to be seen how the German international will react to a summer of wholesale change at Westfalen, following Jurgen Klopp's sacking at the end of last season.

And there's no doubt the 26 year-old is amongst the most formidable and complete attacking threats in world football; famed for his ability to play anywhere across the attacking midfield berth or as an out-and-out striker whilst producing 37 goals and 27 assists in 82 league outings for the Black-Yellows.

Indeed, Reus is equally adept in the roles of scorer or provider, with fantastic movement and vision in the final third. But the 5 foot 11 attacker's defining attributes remain sensational technique and absolutely blistering pace.

Not many surpass Reus in the world-class winger category but following his contract extension last season, Dortmund could realistically demand anything up to £50million for him summer.

GARETH BALE

If nothing were beyond the realms of possibility for Manchester United this summer, I feel pretty confident in assuming they'd fork out a world-record fee for Real Madrid's Gareth Bale without a moment's hesitation.

The Welsh wizard's Bernabeu tenure has been split by two juxtaposing campaigns; one in which his power, pace and goals added a whole new dynamic to Los Blancos' attack; followed by another in which he became a scapegoat for the club's poor form after some admittedly questionable individual displays.

But there's no question Bale is tailor-made for Premier League football, as a counter-attacking threat with phenomenal athleticism, speed, individual skill and the ability to hit the onion bag from seemingly the most audacious of angles.

Resultantly, the 26 year-old's always felt like a Man United player in the making - fitting perfectly with their style of football under Sir Alex Ferguson - and his arrival at Old Trafford would certainly shift the balance of power at the Premier League's summit back towards the Red Devils' favour.

Recent reports claim United have already launched two bids worth around £100million for the former PFA Player of the Year this summer, but clearly Real Madrid aren't too interested in selling.