Aston Villa boss Unai Emery has revealed Diego Carlos hit the training pitch yesterday.
The summer signing from Sevilla broke down at the start of the season.
Emery, delivering an update on their injuries, said: "Diego Carlos, we are so happy, because he has started training with us, yesterday and today. But, of course, he will need time to be fit and to be confident to play.
“Bertrand Traoré is getting better, he trained last week, this week as well, and he is in the squad.
“Olsen has a small problem but he is going to be in the squad as well."
He added: “He (Tyrone Mings) is in the squad (against Arsenal). He trained today and yesterday but we are going to decide tomorrow morning before the match.
“The last moments are going to be very important about the decision if he can start or not."