It's been an interesting few weeks in the world of Sergio Ramos.

Last month, he was a happy as Larry Real Madrid player; now he apparently wants out of the Bernabeu after offering himself to El Clasico rivals Barcelona, and has resultantly become a prime target for Manchester United.

Louis van Gaal wants an experienced defender with quality on the ball, so the former World Cup and Champions League winner, famed for his ability to contribute going forward, fits the bill pretty much perfectly.

There's only one hitch, however; Los Blancos are unsurprisingly reluctant to sell, and have therefore slapped the 29 year-old with a rather incredible £63million price tag - which would make him the joint-fourth most expensive footballer of all time alongside James Rodriguez.

Thus, it's time for the Red Devils to consider some cheaper alternatives, which is where Football FanCast comes in. We've listed FIVE alternatives the Old Trafford outfit should run the rule over, before splashing out copious sums on an ageing defender.

LEONARDO BONUCCI

Real Madrid are reportedly lining up Leonardo Bonucci as a potential Sergio Ramos replacement, so he's on this list as an alternative to the World Cup-winning Spaniard almost by default.

That may seem like a rather indolent approach but no doubt, the 28 year-old is a well-proven defender, boasting four consecutive Serie A titles and 47 caps for Italy - he also played a pivotal role as Juventus reached last season's Champions League final.

He's imperious in the air and an exceptional reader of the game in typical Azzurri style. But Bonucci's defining gift remains his quality on the ball and long-range passing game, having begun his career as a midfielder, which should sit particularly well with Louis van Gaal.

With two years remaining on his current contract, Juve could decide the time is right to cash in on the 6ft. 3" defender. Italians, however, have a knack of rarely venturing far from their nests.

JAN VERTONGHEN

Tottenham defender Jan Vertonghen has never quite rekindled the form that saw him claim a place in the PFA Team of the Year during his debut campaign at White Hart Lane.

But nonetheless, the 28 year-old is still one of the best centre-backs in the division when in top form and he's now a highly-experienced international, with 69 caps for Belgium and a series of appearances at last summer's World Cup.

A product of the Ajax academy and a ball-playing centre-half with enough turn of pace to fill in at left back when required, something tells me former Amsterdam ArenA boss Louis van Gaal will be particularly fond of the multifunctional defender.

Spurs chairman Daniel Levy has made a habit of only selling the club's leading stars to divisional rivals for incredibly lucrative sums - or barring them from leaving altogether, with Luka Modric's non-move to Chelsea being the biggest example.

But with Vertonghen's contract now into its final year, he might be left with little option other than to cash in this summer.

BENEDIKT HOWEDES

Schalke skipper Benedikt Howedes is probably just outside the world's centre-back elite and certainly some way shy of Sergio Ramos in terms of both ability and experience.

Yet, the 26 year-old has a lot to offer Manchester United's squad, as a true defensive all-rounder famed for his ability to perform equally well at either full-back position, centre-half or defensive midfield.

Last summer, he was Germany's left-back during their successful World Cup campaign - which is no easy feat when you measure in at 6ft. 2" - whilst at club level he offers experience, leadership, with 53 outings in continental competitions, and status as being the Miners' skipper since 2011.

The Red Devils have already missed the chance to snap up Howedes on the cheap through a now-expired release clause. But with his contract due to expire in 2017, he's still a plausible target.

NICOLAS OTAMENDI

Manchester United are reluctant to meet Nicolas Otamendi's rather overzealous £35million release clause, but with the pool of attainable centre-backs getting ever smaller, they might not have much of a choice.

Furthermore, the Argentina international was nothing short of sensational for Valencia last season, netting six times in 35 appearances whilst averaging 2.9 tackles, 3.1 interceptions, 7.3 clearances and 3.5 successful aerial duels per match. That's almost 17 defensive actions per match!

He's a little on the short side at just 6ft. and hasn't been exposed to the Champions League or international scene as much as some of the aforementioned names, but regardless, the 27 year-old is a phenomenal athlete with a fantastic reading of the game and is now verging upon his peak years.

Once again, however, £35million is rather steep to say the least.

RAPHAEL VARANE

If Real Madrid are refusing to part with Sergio Ramos, then why not their test resolve regarding Raphael Varane?

The 6ft. 3" defender may only be 22 years of age but he's already recorded a series of significant triumphs in his career, not least including winning the 2010/11 La Liga title, 2014 Champions League title and captaining the France national team.

Despite his limited experience, Varane seems destined for great things. Jose Mourinho has dubbed him the 'best young defender in the world' and indeed, he seems like the total package; formidable in the air, confident with the ball at his feet, an astute reader of the game and an incredible athlete, with pace and power in abundance.

He might not address the current dearth of leadership and experience at the heart of United's defence, but Varane seems as safe a long-term investment as pretty much any player in Europe right now.

He's been pushing for a guaranteed role in Los Blancos' first-team for years, so Madrid's hesitation to part with Ramos could well force the prodigious youngster to reconsider his options.