Saturday’s defeat at West Brom was almost the perfect summation of Patrick van Aanholt’s Sunderland career. Largely culpable for the Baggies’ opener, and miles away for their second, yet the player who came closest for Sunderland and one of their biggest attacking threats, which, admittedly, isn’t saying a great deal on this occasion.

Nonetheless, nobody can deny that the Dutchman is one of the club's most important offensive players, having contributed an impressive seven goals (with two more taken away by the Dubious Goals Panel) and nine assists from left back in his two-and-a-half years in red and white.

But while his performance in defence was nothing new, his lackadaisical approach as he was terrorised by Matt Phillips was one too many for some fans who have grown tired of his deficiencies in his own third of the pitch.

And that left Sunderland and David Moyes in an interesting position. Reports, that had emerged a fortnight earlier, continue to link van Aanholt with a move to Crystal Palace and a reunion with Sam Allardyce, and earlier this afternoon it was reported in the national media that terms with both the club and the player had been agreed in a deal worth around £12M. James Hunter of The Evening Chronicle claimed earlier this evening that the deal was nowhere near as advanced, but that Moyes will not stand in van Aanholt's way. But there's definitely something happening behind the scenes, and it represents an intriguing and perhaps attractive offer, yet one that will no doubt have been tough to assess for the management.

On the face of it, £12M for a defender who struggles to defend - at the critical moments, at least - looks like a decent deal for the club. On the other hand, Sunderland are set to allow one of only four goalscorers this season, and their greatest attacking threat beyond Jermain Defoe, to join a relegation rival. And is £12M enough for a player with that attacking output, considering that an out-of-favour Jeffrey Schlupp was signed for a similar fee?

Regardless, £12M would give Moyes some room to maneuver in the transfer market. Relegation rivals Swansea have signed three players - Tom Carroll, Martin Olsson and Luciano Narsingh - for around that number, addressing problems in areas which Sunderland could do with improving themselves. Time will tell if the trio can make an impact, but Swansea have taken a gamble in the hope of giving themselves a fighting chance, and have shown that there may still be value in an ever-inflating transfer market. Sunderland will look to follow their lead now that funds look to have been raised.

Statistically speaking, van Aanholt surprisingly looks to be a competent defender. Of those who have played more than ten league games games this season, only eight left backs have made more tackles than the Dutchman - 33 of 47 attempted seems like a pretty decent success rate. van Aanholt also ranks as the 5th best left back in terms of interceptions, and the 10th best in terms of clearances made.

But statistics don't always paint the full picture, and from watching him play, it's clear that he is far from a competent defender. Winning tackles, making interceptions and clearing the ball are all well and good, but too many times van Aanholt is caught out of position, ballwatching, or simply incompetent in his play - often with disastrous consequences.

The fact that he ranks as the worst left back (out of 16 who fit the more than ten league games played criteria) in terms of crosses blocked, with just seven, speaks more about him as a defender - too many times he has been chastised for failing to adequately close down his attacker in dangerous areas.

A reunion with Allardyce looks to have tempted van Aanholt for a number of reasons, not least the fact that his best football on Wearside was produced under him. van Aanholt looked a much better player after Allardyce had been allowed to spend £16M on key reinforcements in the January window. The commanding presence of Lamine Kone alongside him, the defensive midfield patrolling of Jan Kirchhoff and Yann M'Vila who shielded the area around him, and the tireless up-and-down effort of Wahbi Khazri, maybe even to the Tunisian's own detriment, gave van Aanholt a great deal of protection and alleviated the constant pressure placed upon the left back position. Allardyce created a system that allowed him to thrive.

But Moyes, up to now, has been unable to replicate that. Khazri, apparently overweight and unimpressive in his (albeit limited) opportunities, is out of favour with the manager. Kirchhoff, as his career thus far suggested would happen, has been injured for the majority of the season, while M'Vila has returned to Russia, leaving Sunderland without a dominating presence in the middle of the pitch. And unfortunately, neither Fabio Borini, nor Duncan Watmore, who if nothing provide tireless energy up and down the wings, have been unable to get on the pitch together. van Aanholt had developed a strong partnership with Victor Anichebe, but the Nigerian's susceptibility to injuries means that they were unable to play together for a long enough period to continue the spark.

There's an argument to be made that Moyes should find a system, by any means, that gets the best out of van Aanholt considering his importance to the team in terms of attacking. The Dutchman has made more passes and created more chances than any other Sunderland player, while taking the second most shots in open play for left backs in the whole league. He's also statistically the best left back in terms of dribbles completed, and only James Milner and Nathaniel Clyne have made more key passes this season.

(It seems hypocritical, or contradictory at least, to acknowledge these attacking stats while dismissing van Aanholt's defensive stats. But truthfully, anyone with half-decent eyesight can see that van Aanholt is a good attacking player and poor defensive player.)

But it's just not practical to build around a left back. The team should be built around Jermain Defoe, or at least built upon a solid defensive base, which van Aanholt has proven that he can't be a part of with his lacklustre defensive displays. Sunderland need to get the best out of all of their players, and not to sacrifice them for the sake of babysitting a left back, no matter how influential they may be in attack.

The club found itself in what is almost a catch-22 situation. One of their best attackers is also one of their worst defenders - while playing as a defender - and a relegation rival was interested.

But Moyes and the powers-that-be appear to have decided to take the risk. £12M, while admittedly not a great deal in the current climate, will give him a bit of space to maneuver in the market. And van Aanholt has hardly been exemplary in recent weeks, with some suggesting his head has been turned by Allardyce. His performances have certainly been far from impressive during this period.

Martin Olsson, albeit in the last year of his contract, was signed by Swansea for around £4M. There may be value in the market. It represents a risk to let the club's only senior left back, one who contributes a great deal offensively at that, leave the club. But it may be a risk worth taking.

Of course, it all depends whether he can be adequately replaced. Hunter suggests that Moyes wants to secure a replacement, or at least have one lined up, before van Aanholt signs on the dotted line. Whether the team tasked with signing players can achieve that is another matter.

But the fact is that Sunderland need to stop conceding silly goals and scoring more, as obvious as that is - again, van Aanholt contributes greatly to both. With limited funds at his disposal - that being 'limited' with a capital L - Moyes, or those above him, look to have been tempted to cash in on one of Sunderland's few saleable assets and give the survival chase one last roll of the dice. And they may just strike lucky.