Manchester United may have already signed four players this summer in the form of Memphis Depay, Matteo Darmian, Bastian Schweinsteiger and Morgan Schneiderlin, but there is still plenty of work to be done on the transfer front.

Indeed, those more philosophical among you might even dare to claim no Premier League squad is ever truly complete. So ahead of a season in which the Red Devils will hope to bag their first domestic title since the resignation of Sir Alex Ferguson in summer 2013, the Old Trafford outfit are certainly still a few top quality signings away from possessing the perfect squad.

Being the ever-helpful bunch we are at Football FanCast, we’ve decided to make Louis van Gaal’s job a little easier by outlining the SIX additions we think could well complete his new-look Man United side.

Would you like to see some of these six turn up at Carrington in time for United’s first fixture of the 2015/16 campaign on August 8th?

PEDRO

Manchester United appear to be pretty much the only major Premier League club not linked with Barcelona’s wantaway winger-forward Pedro at the minute, but with a release clause of £22million he could be a fantastic addition to Louis van Gaal’s squad.

The 5 foot 6 attacker has done it and one it all throughout his spells 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 – and at 27 years is still firmly within his prime.

Former team-mate Alexis Sanchez has changed the face of the Premier League since moving to the Emirates last summer and Pedro, blessed with a similar mix of pace, industry, trickery and netting prowess, has the potential to do the same.

The Red Devils lacked penetration going forward at times last season and despite the presence of Ashley Young, Memphis Depay and Angel Di Maria, another option on the flanks certainly wouldn’t go amiss – especially one with the versatility to play on either side or as a striker should the situation require.

As previously stated, Pedro’s recently penned new contract includes a £22million buy-out fee, but Chelsea are currently the front-runners for his signature.

SERGIO RAMOS

He may cost an arm, a leg and anything up to €90million according to the tabloids, but Manchester United need a star-studded centre-back and Real Madrid’s Sergio Ramos is pretty much the best man for the job.

Louis van Gaal was so desperate to sign Mats Hummels not only for his international experience and leadership, but more importantly for his world-class distribution from the heart of defence and ability to bring the ball into midfield.

The Spain international is of a similar mould, as a former Champions League and World Cup winner famed for his speed, technical flair and knack of popping up in the opposition penalty box.

The only real obstacle is Ramos’ age. At 29, United can’t really justify coming anywhere near Real Madrid’s asking price, so they may be forced to consider some alternatives.

Which brings us onto…

NICOLAS OTAMENDI

Nicolas Otamendi may be a little more orthodox in style than Ramos or Hummels, lacking their front-footed nature and ability to bring the ball out of the back.

But he is a phenomenal athlete and a fantastic defender, last season averaging a near incredible 2.9 tackles, 3.1 interceptions, 7.3 clearances and 3.5 successful aerial duels per match whilst netting six times in 31 La Liga outings. That equates to almost 17 defensive actions per match.

It adds to the 26 year-old’s preceding reputation from his spell at FC Porto, where he helped the Dragons claim three consecutive Primeira Liga titles and the 2011 Europa League title.

If there’s one criticism, however, it’s that the Argentina international doesn’t truly address the current deficiencies of experience and leadership at the heart of United’s defence, which is why United have been reluctant to meet his £35million release clause.

SERGIO ROMERO

Sergio Romero has emerged as a surprise addition to Louis van Gaal’s summer wishlist over the last few days but he does represent a cheap solution to David De Gea’s seemingly inevitable move to Real Madrid.

Rather than spending outrageous sums on a Hugo Lloris or Jasper Cillessen, the Red Devils can simply promote Victor Valdes to No.1 whilst bringing in a 62-cap international as his understudy.

Indeed, Romero is best famed for his exploits with the Argentine national team, featuring prominently at last summer’s World Cup as Albiceleste reached the tournament’s final.

The 28 year-old has struggled for such luck at club level, with only one major trophy to show from his spells with Racing Club, AZ, Monaco and Sampdoria, and now finds himself out of contract after being released by the latter club at the end of last season.

But as a back-up option, United could do a lot worse than a regular international on a free transfer. He’s a smart, experienced and proven shot-stopper more than capable of keeping Valdes on his toes.

Karim Benzema

Manchester United’s strike force struggled to produce a strong goal tally even last season so following the departure of Robin van Persie to Fenerbahce, they definitely need to find another source of firepower this summer.

Coincidentally, rumour has it Real Madrid might be about to scrap Karim Benzema as former Liverpool and Chelsea gaffer Rafa Benitez attempts to implement a new formation at the Bernabeu that will include Cristano Ronaldo as a lone centre-forward.

Blessed with a powerful, aerially combatant and stocky 6 foot 2 frame, alongside the ability to finish immaculately with both feet, the France international is almost tailor made for the Premier League, which is why Sir Alex Ferguson was so desperate to sign him from Lyon in 2009.

He’s since gone on to bag 133 goals in 281 appearances for Los Blancos, which is by no means an almighty sum. But that’s exactly why the 27 year-old could prove to be such a fantastic addition for United; after six years in Ronaldo’s shadow, he’s still got a point to prove.

The tabloids rate him at around £35million, but Arsenal are also interested.

THOMAS MULLER

The word ‘complete’ was brought into existence almost purely to describe Bayern Munich’s Thomas Muller.

He’s a consistent goalscorer with 121 goals in 304 outings for the Bundesliga outfit alongside ten strikes from the last two World Cups – earning him the Golden Boot in 2010 and the Silver Boot as Germany lifted the title last summer.

But that only alludes to a fraction of what the 25 year-old truly offers. In addition to the immeasurable experience of winning a World Cup and a Champions League title at an incredibly early age, he’s perhaps the most complete and versatile attacker in the game today, equally adept at virtually any role in midfield or attack and blessed with an incredible mix of physicality, work-rate, creativity and netting prowess.

Louis van Gaal loves his multifunctional footballers and the 6 foot 1 forward is certainly one of them – in fact, he’s the best multifunctional footballer in the business.

United have already been linked with a series of bids this summer but Bayern are understandably reluctant to sell.