Earlier in the week, transfer speculation suggested Arsenal are seriously contemplating a €10 million move for Swansea captain Ashley Williams.

It was no surprise that the Gunners have been linked with a defensive reinforcement in the same week that skipper Thomas Vermaelen and Per Mertesacker suffered lapses in concentration in the North London derby defeat.

Vermaelen was an excellent purchase initially after moving from Ajax in 2009, impressing in his debut season as a tough goal-scoring defender and making the PFA team of the year.

But the 27-year-old’s development stalled after missing the bulk of the 2010/11 season with a serious Achilles problem, while injuries also affected the following season. Added to stints in an unflavoured left-back position, the ‘Verminator’ is a pale imitation of his former self.

Mertesacker and Laurent Koscielny have also failed to convince during their time at the club with the German in particular seemingly unsuited to the pace of the Premier League.

Key figure

On the other hand, Swansea’s Williams has been a key figure defensively as the Welsh side have established themselves in the Premier League.

Also linked with Liverpool due to his connections with Brendan Rodgers, the 6ft centre-half has been a consistent presence in a team that also likes to play out from the back.

His passing accuracy is much the same as Vermaelen’s in both halves of the pitch, although both players are inferior to Mertesacker in this regard.

However Arsenal will surely be more concerned with his defensive attributes. Aerially, Williams and Vermaelen have won about 56 per cent of their duels. Understandably the 6ft 6 inch Mertesacker has won a higher proportion although given his height and presence he appears to the lack natural aggression that is necessary in the Premier League. Arsenal have improved significantly in the air, with the third highest proportion of headers won in the league, predictably behind Tony Pulis’ Stoke and Sam Allardyce’s West Ham.

But the Wales international has won a greater percentage of tackles than his German counterpart at 73 per cent, although Vermaelen overshadows both players at an impressive 83 per cent.

Leadership ability

However it is the defensive reading of the game that has let Arsenal down in recent years coupled with a brittle offside line.

And that is evident when you compare the number of interceptions made by Williams, Mertesacker and Vermaelen in teams that average over 55 per cent of possession.

Williams has made 2.6 interceptions per game, vastly superior to Vermaelen (1.9) and Mertesacker (1.7).

His leadership ability could also be beneficial in a team often accused of lacking strong characters, having captained club and country.

Arsenal have also been linked with Athletic Bilbao’s rugged centre-half Fernando Amorebieta. But personnel changes alone will not solve Arsenal’s issues. Arsene Wenger will need to entertain the thought of giving assistant Steve Bould free rein to organise the back four, while finding alternatives to playing an offside trap need to be considered.