The Portuguese defender missed all five matches in November with a calf problem but returned at the start of December and has been an ever-present this month.
However, Guardiola says that Dias’ run of starts will come to an end when we play Aston Villa on Saturday while he is also currently unsure about Ederson‘s fitness.
“Ruben is out for a long time and Ederson I don’t know if he will be ready tomorrow,” he said in Friday’s press conference ahead of this weekend’s game.
“[On Dias] Three or four weeks. Muscular.
“[He played] 75 minutes against United. He felt something but he is so strong and wanted to stay on the pitch.”
City have suffered significant injury problems so far this season, with the backline perhaps most affected.
Nathan Ake remains out but there was positive news on an availability front with Manuel Akanji and John Stones back in full training.
The Swiss international was forced off at half-time of the victory over Nottingham Forest earlier this month while Stones hasn’t been on the pitch since the November defeat to Spurs.
“Manuel and John are back in training,” he said.
“That is good for us. As many players that are back the better.
“I don’t know yet [if they can start against Aston Villa]. Yesterday was their first training session, I would say, properly. They have been out for a while.”
Rico Lewis, who was suspended for last week’s Manchester derby, is now available to return to the squad.
City head into this weekend in a difficult run of form that has seen us slip to fifth in the Premier League table.
Unai Emery’s Villa sit two places and two points behind us before kick-off, as they adjust to juggling domestic commitments alongside the Champions League.
Guardiola was full of praise for his opposite number ahead of tomorrow’s meeting.
“Top, excellent manager who has handled many things. Their results in Champions League for themselves,” he said.
“They have done really, really well. They have a long squad, it is really good. In those terms it is nice.”
Aston Villa v City app coverage
Minute-by-minute text updates will begin in our Matchday Centre two hours before kick-off, while our Matchday Live show will begin at around 11:15 (UK).
Keith Curle and Andy Morrison will be the guests on the latest Matchday Live show, offering their expert insight before, during and after the action.
During the game, you can also listen to live audio commentary from Alistair Mann and Michael Brown while our text commentary continues.
Make sure to have push notifications turned on as well, so you can be alerted to key moments in the action, including goals, red cards and the team news.
Short highlights from the match will be available from 16:30 (UK), whilst extended highlights from the encounter and a full-match replay [available on CITY+] can be accessed from midnight.
