They may not receive the largest headlines or the biggest pay cheques, but full-backs have become arguably the most important players on the pitch over the last few decades.

It's one of the few positions where you actually get time on the ball in attacking areas and the mentality of the full-backs tends to correspond to the mentality of the team; whether they're pushing up to support the attack, sitting deep to protect their centre-halves or balancing their duties somewhere in between.

Similarly, full-backs in the modern game - and particularly since Barcelona's four years of unparalleled dominance under Pep Guardiola - now operate almost as the wide men, providing width in attack to let the wingers tuck in and get closer to the goal.

Unfortunately for Guardiola, however, the Manchester City squad he's about to inherit from Manuel Pellegrini isn't exactly overflowing with top-class full-backs. Pablo Zabaleta appears a little beyond his best, Bacary Sagna is decent if unspectacular and Aleksandar Kolarov and Gael Clichy just haven't been up to task this season. Rather tellingly, they're now all aged 30 or over.

So with that in mind and energetic full-backs a particularly important part of the Guardiola philosophy, we at Football Fancast have been running the rule over five more youthful replacements to City's ageing clan. Which of these full-backs would be the ideal signing to kick off the Guardiola era at the Etihad?

DAVID ALABA

David Alaba has already been linked with a summer move to Manchester City and the Bayern Munich defender would be a fantastic swoop for Guardiola's first transfer window.

Indeed, the 23-year-old is already up there with the best left-backs in world football - in fact, many would claim he's at the top of the pile - but his qualities are by no means restricted to the no.3 position.

He's featured regularly at centre-back, left midfield, left wing-back and central midfield throughout his career, filling the latter position frequently during his 42 outings for the Austrian national team, and is one of the most well-rounded footballers in the game today.

Guardiola loves his multi-purpose players and is clearly a big fan of Alaba, issuing the versatile starlet 103 appearances during three campaigns at the Allianz Arena helm.

The tabloids rate the Vienna-born utility man at around £40million and with two years remaining on his contract, the summer represents City's best chance of convincing Bayern to sell.

HECTOR BELLERIN

Arsenal players have a knack of jumping ship to Manchester City and I'm sure supporters of the latter club will be hoping young right-back Hector Bellerin is prepared to follow that trend.

The rip-roaring performances of Dani Alves were crucial to Pep Guardiola's successes at Barcelona and the Gunners starlet is a similar kind of mould, as a converted winger blessed with incredible speed, technical quality and a willingness to contribute going forward.

Indeed, he's emerged as one of the most exciting full-backs in world football since becoming an Arsenal regular last season, providing penetrative pace on the overlap and cover for the notoriously slow Per Mertesacker, and is still just 20 years of age.

I feel Guardiola can get even more out of the Spain U21 who, as a product of Barcelona's famous La Masia academy, will surely be desperate to work with the former Nou Camp boss.

Of course, whether Arsenal would be open to selling remains the ultimate question mark. Bellerin's contract doesn't expire until 2019 and they'll be desperate to keep hold of one of their most exciting young players.

Ricardo Rodriguez

Few full-backs in Europe have matched Ricardo Rodriguez' potent output over the last few seasons, notching up 13 goals and 20 assists in his last 100 Bundesliga outings for Wolfsburg.

His dead-ball mastery is a predominant source but the Switzerland international's impact on open play should not be overlooked, averaging 1.9 created chances, 1.9 tackles and 1.9 interceptions per match this season.

The 23-year-old isn't the quickest compared to some of the other names on this list but his technical quality certainly fits into the Guardiola philosophy - he's almost the Bundesliga's answer to Everton and England star Leighton Baines.

After four solid seasons at the Volkswagen Arena, the timing feels right for the 33-cap international to move on. Plenty of top European clubs are interested but under contract until 2019, Wolfsburg are in a strong position to command a hefty fee.

Rodriguez could realistically set the Citizens back around £30million.

ALESSANDRO FLORENZI

A similar mould to David Alaba, albeit on the opposite side of the pitch. Indeed, Alessandro Florenzi has featured as a central midfielder and a winger throughout his Roma career but produced arguably his best form since becoming their resident No.2 last season.

The Italy international's technical quality is evident enough through his Puskas award nomination last year - even making it onto the three-man final shortlist - for his unforgettable long-range strike against Barcelona.

He also reads the game incredibly well going forward - almost like a midfield playmaker - but the 24-year-old's industry, energy and tenacity equally stand out and is making him a real fan favourite at the Stadio Olympico. He even wore the captain's armband against Real Madrid last night.

A number of major clubs are already looking at the versatile Italian, including Arsenal, Tottenham Hotspur and Barcelona. But Rome-born and a product of the Giallorossi academy, many expect him to follow the paths of Daniele De Rossi and Francesco Totti by rejecting interest to become a one-club man.

SERGE AURIER

He may be one of the most unpopular players in Europe at the minute, having made derogatory remarks about Laurent Blanc and some of his PSG team mates on camera, but Serge Aurier was enjoying incredible form before the scandal broke last weekend.

Indeed, he's averaged 3.9 tackles, 3.6 interceptions, 1 shot and 1.2 successful dribbles per match in Ligue 1 this term and produced similar statistics in the Champions League - where he's also found one goal and one assist from just three outings.

Admittedly, the Ivory Coast international isn't much of a technician compared to the other names on this list and therefore, probably the least suited to the Guardiola philosophy.

But he's a phenomenal athlete, a smart and incredibly versatile defender, who has featured as a full-back, a wing-back - on both sides of the pitch - and a centre-half throughout his career.

Aurier represents a more balanced option that could take Guardiola's fancy and the aforementioned scandal could well force PSG to sell in the summer. He's currently suspended indefinitely.