Tottenham winger Gareth Bale has attracted widespread interest from some of the top clubs in Europe over the course of the past 18 months, with Barcelona and Real Madrid prime among them, but just how realistic is a move to one of Spain's big two?

The main stumbling block to any deal to one of La Liga's hegemonic duo is the price above all else. When you look at his value to Andre Villas-Boas and how integral he is to the squad, the price of around £40m often mentioned seems around the right mark. The club have no pressing need to sell and having just sold Luka Modric to Real Madrid for north of £30m, nor will they want to start repeating the trap that Arsenal have fallen into the last few years of selling your best player each summer - a vicious cycle if ever there was one.

It's clear that the money floating around the Camp Nou isn't quite as rich as it once was, and if Tito Vilanova were to sanction a move for Bale around the €40m (£32m) mark, still significantly less than what Tottenham would deem an acceptable price for their man, then they would be blowing the vast majority of their transfer budget on one player, something that they will be loathe to do.

You also have to ask yourself, where exactly would he fit in to this current Barcelona side? The club's acquisition of Spain left-back Jordi Alba from Valencia in the summer for the modest amount of €14m (£11m) on the face of it would appear to end any need for the club to pursue Bale in the future and he may have missed his chance.

Alba came through the ranks at La Masia before leaving the club after failing to break through into the first-team, finding his success elsewhere first like both Cesc Fabregas and Gerard Pique before him; a continuation of a fairly expensive transfer policy of bringing former players back to the club.

However, his success this term can be directly attributed to how familiar he is with the style and methods of the club so ingrained into their younger players and at just 23 years of age, he's a long-term purchase. This means that the previously assumed role at left-back as Eric Abidal's successor is no longer available, so would he fit in further up field?

Bale has shown that he can be effective drifting in off the flank at times, but far too often this has a more detrimental impact on the balance and overall threat of the rest of the side. He has displayed the ability to play quick one-touch football through the middle, with his goal away at Manchester City last term a testament to that, but it's clearly not his natural game.

No, the Welshman is at his best when running onto a ball at pace or driving into the space in front of him. The possession-based game that Barcelona play means that the only position he'd be able to do that from is as an attacking full-back, and unless he actually bothers to develop a right foot any time soon that he can use consistently enough, I simply don't see that happening, even if question marks remain over Daniel Alves' future at the club beyond the end of this season.

Alexis Sanchez has at times struggled with the little space he receives closed in around the box and his natural game has been restricted somewhat and you could see Bale suffering in the same way in a more advanced role. He doesn't possess the skill to beat a player at close quarters that a Cristiano Ronaldo or Luis Suarez does. Moreover, the likes of Christian Tello, Isaac Cuenca, Pedro and the exciting and emerging talent of Gerard Deulofeu would mark Bale's purchase as a needless indulgence in an area where they are well stocked, with buying a recognised centre-half, rather than a versatile holding man capable of filling in seemingly a much more immediate and higher priority.

Speaking of Cristiano Ronaldo, he is the player which Bale is often compared to and he has developed that arrogant swagger in recent times. The 23-year-old has shown a worrying lack of work-rate in tracking back to help out his defender this season, almost as if he views it as beneath him and it's no coincidence that both Manchester City and Arsenal absolutely tore Tottenham's left flank apart in recent games. Off the ball, he is not only positionally naive and tactically unaware, it has got to the point where that area of the pitch is being targeted and it's costing them in important games; for an arch pragmatist such as Jose Mourinho, you suspect that might be something of a problem looking further ahead.

As part of Luka Modric's £33m move to join Real Madrid this summer, the two clubs signed a 'commercial partnership' deal, with Tottenham set to reap the benefits from this transfer long after the Croat has retired from the game, but part of that arrangement had many suspicious about what Tottenham may have given away to secure that lucrative relationship, with a first option on Bale the rumoured benefit for the Spanish giants.

When you look at the Real Madrid squad, they play a much more expansive, counter-attacking style of play than Barcelona, which would seem to suit Bale down to the ground a lot more and you could imagine him in a more advanced role on the left wing at the Bernabeu, particularly with Angel Di Maria continuing to frustrate and excite with almost crushing regularity, and his inconsistency could see Mourinho look elsewhere.

They seem pretty well set at left-back, with the excellent Marcelo and disappointing Fabio Coentrao left to battle it out for a starting spot, but despite the Portuguese international's struggles since moving from Benfica, the club parted with €30m (£24m) just last summer, so for Mourinho to give up on him now before he has truly shown his best form would represent something of an embarrassing climb down and confession of a flawed transfer; a move which he is unlikely to sanction at the risk of handing the critical Spanish press more ammunition.

There's no denying that Bale would not sit comfortably in both of these sides, for he has occasionally shown the form and standard required, even if he looks incapable of doing it for prolonged spells at the moment. Aside from him not being quite ready to make the step up in my eyes, I just can't see either club wanting to part with a fee of around £40m for someone neither of them realistically need to still compete at the highest level. You have to ask yourself, would he improve either side that much to warrant such an outlay?

The artificial inflation of British players means he could be priced out of any future move and while he may desire to move elsewhere further down the line in the pursuit of silverware, a move to either Manchester club would make much more sense. At the moment he is worth £40m to Tottenham but someway short of that for the Spanish pair, and bridging that divide remains the biggest stumbling block of all.

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