Arsenal duo Ozil, Sanchez in line for Chelsea

German playmaker Ozil missed last weekend's 0-0 draw at Stoke City with a minor foot injury, but Wenger said that he would be available for the London derby at the Emirates Stadium.

Wenger is also hopeful that Sanchez will be able to feature for the first time since succumbing to a hamstring problem at Norwich City on November 29, although the Chilean is not certain to be involved.

"The good news is that Ozil certainly will be available," Wenger told his pre-game press conference at the Arsenal training ground.

"Sanchez, the next two days will be decisive, but this time, I think he will make it for selection."

On Sanchez, Wenger added: "The doubt is about him having been out for a long time, and the risk of a setback.

"To be clear on all the tests is one thing. To be clear after training is another. The intensity of a big game you can never replicate in training, but you can make the risk minimal.

"I'm cautious with him because we cannot afford a setback, which would mean a very long period out. We don't want to take this risk. The signs he's shown in training this week are positive."

Wenger said that midfielder Francis Coquelin had returned to full training on Thursday following a knee injury.

Striker Danny Welbeck (knee) is due back in training next week and midfielder Tomas Rosicky is scheduled to play for Arsenal's under-21 side on Friday as he pursues his recovery from a knee injury of his own.

Arsenal top the table on goal difference from Leicester City, with Manchester City a point back in third place. Chelsea are 19 points adrift in 14th.

Wenger also said that he would happily help UK Anti-doping after the agency's chief executive, Nicole Sapstead, said on Wednesday that she wanted to speak to him about comments he has made about doping in the past.

Wenger, 66, said in November that football had a doping problem and accused European governing body UEFA of not doing enough to stamp it out.

"I have more desire than time, but I'm more than happy to help if I can in clarifying things for people who want to fight against doping," he said on Thursday.

"I've said what I have to say. In football, in our job, we look like we want to tackle the problem now. For a long period it looks to me like we didn't.

"I am available. We have to tackle doping and fight against it, you and me. I am not thinking I can do more than people responsible to do that, but if they need to talk to me, I'm available."

He added: "I'm sure that not one club in England is trying to dope its players."