Arsène Wenger has given Alexis Sanchez a “slight chance” of facing Manchester City on Monday as the Arsenal forward steps up his return from injury in training.

The Chilean has been out with a hamstring strain for the past three weeks and has not yet started participating with the rest of the squad at London Colney. But Sanchez has been out running, giving Wenger some hope that the £30m forward might be able to play some part at the Emirates in three days’ time.

“Everybody who played against Aston Villa is available for Monday night and there are one or two possible comebacks,” Arsenal manager Wenger said at his press conference yesterday morning. “Maybe there is a slight chance for Alexis to be in the squad, but it is too early to be sure about it. He is running, but not participating in full training.”

Sanchez injured his hamstring in the 1-1 draw at Norwich City on 29 November and was initially expected to be out for most of December. He has already missed three games: the 3-1 home win over Sunderland, the crucial 3-0 victory at Olympiakos in the Champions League, and the 2-0 win at Villa Park in the Premier League last Sunday.

The striker is renowned for his enthusiasm to play and Wenger said he would have to make the decision himself, regardless of what Sanchez tells him.

“Alexis says he is always ready,” Wenger said. “Some of the players are so keen to forget that they have pain somewhere that they say they are alright when they are not.

“You know the players, and their psychological profile, you take that into account, get scientific advice, and trust your gut and make a decision. It is normal that Sanchez wants to play, you want him to be keen to play. He respects all the decisions that I make, and that is what I want from him.”

Wenger spoke about Arsenal drawing Barcelona in the last 16 of the Champions League, and how their exits to them in the Champions League in 2010 and 2011 remain “deep in his bones”. Arsenal were beaten by four Lionel Messi goals in the second leg of the quarter-final in 2010, and lost 4-3 in the last 16 in 2011 after winning the first leg at the Emirates 2-1. Now Wenger said they can “put things right”.

“We are more mature,” he said. “We played against Barcelona with top teams, but very inexperienced and very young. Barcelona were in full power but we still managed to beat them and it was always very tight.

“We have never been beaten [comprehensively] and we were sometimes unlucky as well. That is in our minds. That is deep in my body as well. I do not forget that. We have a chance, an opportunity to put things right, and we’ll focus on that.”