Arsenal’s long-simmering defensive issues came to a disastrous head on Tuesday night when Arsène Wenger’s men let slip a 3-0 lead against Belgium visitors Anderlecht. The 3-3 draw meant Arsenal lost a golden chance to secure early passage to the last 16 of the Champions League and, likely more significantly, all but ended their chances of finishing above Borussia Dortmund and topping Group D. Such a drastic collapse against the inexperienced Belgian visitors earned boos from many inside the Emirates Stadium as well as strong criticism from Arsenal’s manager.

“We had a poor defensive performance from the first to the last minute today,” Wenger said in his post-match press conference. “We never felt comfortable and somewhere we got punished, because of a bit of bad luck -- because the first goal was offside, clearly -- but defensively our performance was not good enough to do it.”

Arsenal’s defense was again weakened on Tuesday, with left-back Nacho Monreal lining up alongside Per Mertesacker in the center of their backline. Injuries have deprived a defense already lacking in depth of Mathieu Debuchy and Laurent Koscielny in recent weeks. And this latest performance will only increase calls for Wenger to fulfill his stated intention to bolster his rearguard in the January transfer window. Wenger, though, refused to expand on the subject after the disappointment against Anderlecht.

“Honestly it’s not the worry tonight,” he said. “We just came off two clean sheets and maybe we thought we had the job done at 3-0. The target is to come back against Swansea with another defensive performance.”

Having failed to replace Thomas Vermaelen in the summer, Arsenal now face the more tricky task of trying to lure players away from their clubs in midseason. One defender they may have success with is Winston Reid. The West Ham center-back’s contract is set to expire at the end of the season and his club has revealed that attempts to tie him down to a longer deal have hit a roadblock.

“Things are not really progressing but we’re hoping his agent will come to a meeting in the next few weeks,” a spokesman said, reports the London Evening Standard.

Signed following his impressive performances at the 2010 World Cup in New Zealand, Reid made a slow start to his time in the England but he has since established himself as one of the Premier League’s more impressive defenders and a key figure for West Ham. They are likely to face strong competition for his future services, with Arsenal as well as Liverpool and Manchester United linked with a move. West Ham may be tempted to do business on a cut-price January transfer if it appears that Reid is set on walking away for nothing at the end of his contract.

There have been encouraging signs, too, regarding another highly rated central defender to have been repeatedly cited as a target for Arsenal in recent times. Fabian Schar’s stock has risen considerably in recent years on the back of his European performances for Swiss champions Basel and his elevation to the Switzerland national team. Like Reid, he will be out of contract next summer, and the 22-year-old has left no doubt that he has his sights set on a major European league.

“Basel would always be open for negotiations, but right now I have decided that I want to focus on my performances,” he told Swiss publication Blick. “I had a difficult period when it would have been the wrong time to discuss my renewal. I don’t want to worry about that now. The dream of playing abroad is strong. I’ve always said, of the possibility is there, I want to grab it, providing Basel agree.”

The situation is reported to already be more advanced regarding another Swiss defender currently set to be a free agent at the end of the season. Sky Italia reporter Gianluca di Marzio has stated that Stephan Lichtsteiner remains in discussions over a new deal with Juventus, who are keen for him to stay, but that Arsenal have made contact with the player’s representatives.

The attack-minded Lichtsteiner has generally operated as a right wing-back for the Italian champions, meaning he would be a risky choice to fill the right-back slot at Arsenal. He would also appear a strange target, given the summer arrivals of France right-back Debuchy and the man currently occupying the position, Calum Chambers. The interest may, though, signal Wenger’s intention for Chambers to be used as a center-back.