The rumors have begun regarding possible exits and entrances at the Emirates over the summer, the latest suggestion is that Gallas will be leaving during the transfer period. At 31, Gallas certainly fit's the traditional profile of a Wenger sale, but he is a top performer in an area where Arsenal need to strengthen, even with him in the squad.
Wenger has already highlighted the defencive area as the key to Arsenal's disappointing season. The fact that Arsenal scored an identical number of goals in the league as the champions Manchester United, yet conceded 13 more than them (a whopping 45 percent more) illustrates just how right he is.
Gallas and Toure make a formidable center back pairing, unfortunately during the '08/'09 season all too often either one or the other has been unavailable and there hasn't been the strength in depth in this position to compete at the highest level with these absences.
Silvestre's signing was an attempt to shore up this area with experience, his performances however have let the club down in a big way.
His speed and agility are well below the necessary level and at his age (31) a lack of games is even more influential at exacerbating his apparent lack of sharpness. If Gallas is being considered for sale, then certainly so too should Silvestre.
Additional support in this role comes in the form of the swiss pairing of Senderos and Djourou. Both of them have massive potential for the future but are they ready to be considered regular first team picks for the big games?
Judging by Djourou's performances, especially in the 1-3 home defeat to Manchester United in the Champions League, he's not quite ready yet.
Song's fill in job at the close of season illustrates his possible potential in this role, but he doesn't have the positional experience under his belt to really provide a solution in the short term.
So what would be the answer? Another over the hill centre back? Another inexperienced young gun? No, there is a dire need for a top quality, peak age (24-29) centre back signing, two if Gallas is departing. But who?
Philippe Mexes would be the ideal signing. At 27, he is at his peak with plenty of experience and young enough to provide at least another 4-5 years of regular appearances.
However he has stated he would like to play out his career at Roma and after recent interest from AC Milan he has reiterated his desire to stay.
However, Roma will not be in the Champions League next year. There is uncertainty over Spalletti's future at Roma (his presence being a stated reason for Mexes wanting to stay), and with the World Cup coming up next summer, he might possibly be tempted by an opportunity to play for Arsenal, where he would no doubt flourish under his fellow Frenchman Wenger.
While there was already rumour of a Gallas sale and Mexes purchase during the 2008 winter transfer window, when Milan showed interest a £30-35 million price was estimated, which would currently seem a prohibitive price for the current Arsenal finances.
Giorgio Chiellini seemed a more likely prospect, with rumors of Wenger showing an interest in him and Juventus's Ranieri wanting Gallas (the player he introduced to the EPL), a possible trade plus cash deal could have been on the cards. Ranieri's departure as Juventus Manager changes the situation some what though.
However, with Cannavaro set to return to Juventus for next season this could still be a possibility. At only 24 he already has lots of experience and represents further potential for the future. His performance against Spain in Euro '08, where he was able to silence the front pairing of Torres and Villa, illustrated exactly how good a defender he is.
Brede Hangeland has been touted as another possible target. He has impressed at Fulham and played a pivotal role in helping them secure their highest ever Premier League finish, with the fourth best defencive record in the league.
At 27 the Norwegian fits the profile of exactly what Arsenal require, and his 6'5" stature would certainly add some needed height to the Arsenal back line. Premier League experience and the leadership qualities he displays as national team captain also make him a very attractive proposition.
There have already been rumours of an £8 million offer from Arsenal, which would be a good return on a payer who only cost £2.5 million one and a half years ago.
The noises from the Fulham camp are that he's happy to stay and will be offered an extension to his current two-year contract; however it was reported that he had already rejected a contract only a month ago.
Thomas Vermaelen is a player that Arsenal have been rumoured to be looking at and are preparing a £7.5 million offer for. However at only 23 years old and 5'11", he wouldn't really bring the experience and physical stature that is needed at the centre of the Arsenal back line.
He is a versatile player though, who can also play at left back. If Clichy was to depart then he would seem a likely candidate to replace him, as a replacement for Gallas however he doesn't fit the required profile.
Per Mertesacker be a strong addition to the club. At 24 he still has a long career ahead of him, yet already has plenty of experience. His 6'6" would add much needed height and he is a quick player for someone of his size.
He has international level experience, playing in the Champions league and reaching the 08/09 final of the UEFA Cup with his club, as well 55 games under his belt for the German national team.
It seems likely that he will be leaving tenth placed German club Werder Bremen in the summer. However there has already been reported interest from Bayern Munich, AC Milan and Wolfsburg, with Munich seen as front runners in the chase.
Because of this interest from two very big clubs, Arsenal would be very lucky to capture his signature.
Robert Huth has been another suggested candidate and with Middlesborough's relegation he will likely be available for transfer.
While he has experience and physical stature, his performance for Middlesborough in the '08/'09 season should make this one a no starter—reliability is the number one characteristic of a top quality center back, and he hasn't shown that in the past year.
Joseph Yobo is another rumored potential target. At 28, he is at his peak and while only 6'1" he wouldn't be the tallest potential target he certainly is physically strong. Also his level of experience in the EPL is a very attractive quality.
However we've been here before.
In 2006 delays in the signing of a new contract led to rumours of a possible switch to Arsenal that never materialised. Wenger has previously stated he's an admirer, but signing the third choice centre back from your closest rival outside the "big four" does not scream ambition.
While one to have an eye on, I think there are better candidates for the job and a potential free transfer in a year would constitute a much better prospect.
In my opinion the best option would be the signing of both Hangeland and Chiellini. Hangeland's experience in the EPL would mean he would not need time to adapt to English football and add instant strength to defending the set piece situations that Arsenal have looked vulnerable at.
Chiellini would no doubt need some time to adapt to the pace and style of English football, but could prove to be a vital ingredient in those big games (like both this season's semi-final exits) and mature at a pace with the other key Arsenal players of the same age.
With the possible exit of Gallas and Silvestre, Arsenal would then have three mature centre backs competing for places, which is always a healthy situation. When necessary it could also provide the opportunity for Toure to at times venture back into his early career role of defencive midfielder.
The big question however would be the financing of these transfers. At a net cost of probably £20 million (with the sale of Gallas and Silvestre) this would seem to be beyond the reach of Wenger's budget and might ultimately be dependant on either other transfers or assistance from Arsenal's two largest stakeholders...