Carlo Ancelotti has confirmed Alex will start Chelsea's Premier League trip to Birmingham City but admits the defender still requires a knee operation.
The Brazilian stopper missed the Blues' 3-0 defeat to Sunderland last weekend through injury and was due to spend a lengthy spell on the sidelines.
But the former PSV Eindhoven centre-back was called up for Brazil's friendly with Argentina in Qatar in midweek, suggesting the 28-year-old's health concern was not as bad as first feared.
And while Ancelotti has revealed Alex is fit enough for the trip to St Andrews, the Italian tactician admits the defensive stalwart will have to go under the knife at some point in the near future.
"Tomorrow Alex will be available, which is good news. He trained well for the Brazilian team," said Ancelotti.
"We know he needs surgery, but we can procrastinate for this. There's no risk, but his knee needs to be clean.
"It will be good to have him back. We didn't play well last week, played a poor game. It was the first time in my period here, so we need to move on immediately and have a reaction.
"The reaction will not be because we have got Alex back. We'll have a reaction if everyone works for the team, works hard and shows a good mental attitude and fighting spirit.
"Our aim is to play well, better than we did against Sunderland. We want to forget Sunderland with a fantastic performance.
"If we play well, we can win and maintain our position at the top of the table."
What will be the outcome in the match Birmingham vs Chelsea?