Arsenal’s defensive options will be further stretched against Newcastle United on Saturday, with neither Laurent Koscielny nor Nacho Monreal fit to return and Calum Chambers suspended. Chambers was sent off in a defeat to Stoke City last weekend that saw an Arsenal defense missing Koscielny and Monreal torn apart in the first half. Arsenal went into the season with just six senior defenders, and have been blighted by injuries at the back throughout the campaign. A clash with a Newcastle team fresh from ending Chelsea’s unbeaten start to the season is now set to provide another stern test.

“Our main problems are still defensively because Laurent Koscielny looks like he will not be quite ready, Nacho Monreal is not back and Calum Chambers is suspended,” manager Arsene Wenger said on Thursday, according to Arsenal’s official website.

There is some positive news, with Mathieu Debuchy having made his return to action in a 4-1 win over Galatasaray on Tuesday. Yet, with the French right-back having played more than 75 minutes after three months out following ankle surgery, there may be some hesitation about starting him again. Last week, Wenger spoke of the risks of pushing a player too soon after injury.

“The hardest part is when a player has been out for three months is to decide do you put him in straight away and risk that he has a big setback or do you wait one more week,” he said. “But you have the urgency of the result that is of course very big. And therefore you have to take a calculated gamble.”

Arsenal also have a doubt about the fitness of midfielder Aaron Ramsey. The Wales international scored a stunning goal in Turkey in midweek, but was then taken off at halftime after suffering a hamstring problem. “Aaron Ramsey will be checked today and tomorrow, so we’ll see,” Wenger said on Thursday.

Were Ramsey not to make it for Saturday’s clash at the Emirates, Arsenal would also be left short of options in central midfield. Captain Mikel Arteta is “not ready,” according to Wenger, as he continues to be troubled by his latest calf complaint. And Jack Wilshere remains a long-term injury casualty after undergoing surgery on his left ankle late last month. Newspaper reports earlier this week suggested that Wilshere had suffered a setback in his recovery and would be out longer than the initial 12-week prognosis, but Wenger has insisted that is not the case.

“That’s completely wrong,” he said. “He’s doing very well. He’s on crutches so I don’t see how he can have a setback. It’s frustrating because it’s hard enough for Jack to be injured. He doesn’t need the negative news on top of that. It’s always frustrating to deny things that are not true.”

Theo Walcott returned from his own lengthy injury absence last month after 10 months on the sidelines. But following two substitute appearances, his progress has been halted by a groin injury picked up while on international duty. And the England international will again be out this weekend, despite being back in training.

“The signs are quite good,” Wenger said. “He has had two days of training now but he now lacks competition and fitness to come back to a good level.”