Theo Walcott Arsenal
Theo Walcott has seen his Arsenal comeback hampered by a persistent groin problemReuters

Defence is again going to be the major worry for Arsenal manager Arsene Wenger ahead of their English Premier League game against Stoke City on Saturday.

In the midweek game against Southampton, the major issue was at left-back, with Kieran Gibbs and Nacho Monreal both picking up knocks in the game against West Brom last weekend.

However, both players came through, with Monreal starting, but that will not be the case this Saturday, with the Spaniard ruled out for the trip to Stoke.

Wenger is hopeful, and no doubts has plenty of fingers crossed, that Gibbs will be fit and available for what promises to be a bruising match at the Britannia.

"We have to assess a few players today because we had some bad surprises with Nacho Monreal being out for tomorrow's game," said Wenger on Friday. "Hopefully Kieran Gibbs will be available and back in the team."

The defensive worries have not eased there, with Laurent Koscielny a doubtful starter as well, as the centre-back continues to struggle with that Achilles problem.

"We have to assess some other players like Laurent Koscielny and a few bumps and bruises that we got after the game," added Wenger.

"I would like him to play a third [game after coming back from injury] because he is a very important player in our squad, and ideally he will be available tomorrow. That decision will only be made tomorrow morning."

Koscielny has been impeccable for Arsenal since returning to action last weekend after nearly two months out, and if the France international cannot make it to the game against Stoke, and assuming that Gibbs is also out as well, then Wenger will have some serious problems at the back.

Calum Chambers can fill in at centre-back, with Hector Bellerin an option at right-back, but then left-back will be an issue. Wenger has the option of using the young and raw Isaac Hayden as a central defender, leaving Chambers to fill in at fullback alongside Bellerin.

That is hardly the scenario that Wenger will want to find himself in, particularly at a ground where there will be no quarter given, and the manager will hope, at least, one of Koscielny and Gibbs make it.

Right-back Mathieu Debuchy is back in training, but this game comes too soon for the defender who has been out since early September with an ankle injury, while goalkeeper Wojciech Szczesny could make it to the starting lineup, even though Emiliano Martinez has done pretty well in his place.

"Szczesny will be back today in full training," said Wenger. "I don't know if he will be completely available or not yet. Debuchy is also back in training but it's too early for him.

"The earliest he could be available is maybe on Tuesday [for the Champions League game against Galatasaray]. I don't know whether I will take him yet because we are short number wise."

Tomas Rosicky, who has only seen a handful of minutes all season, and Yaya Sanogo are doubtful starters with thigh and calf injuries, while Theo Walcott remains sidelined with that groin problem he picked up while on England duty, with the forward also ruled out of the midweek Champions League game.

Walcott's injury problems will be a cause for worry, with the forward unable to get those precious minutes necessary after making a comeback from a long-term injury.

"Walcott is still struggling with his groin inflammation," Wenger said. "I think he has an injection today to take care of that.

"Hopefully he can be available again after that. Galatasaray will be too early for him."

With Alexis Sanchez in the "red zone" as Wenger revealed, Arsenal could certainly do with the return of Walcott as soon as possible.