The Uruguay international will be absent against bottom side Malaga – winless in seven league outings – but could return in the aftermath, with the Europa League last-32 tie against Copenhagen coming up.
Simeone told a pre-match news conference: "Diego won't play, but he's recovering well.
"He is really strong mentally and that is helping him to recover within the deadline the doctors said.
"If everything keeps going like it should he will be back with the team by next week. Jose [Gimenez] and Lucas [Hernandez] will be in the starting 11 [against Malaga]."
Atleti will have left-back Filipe Luis available once again, though – the Brazilian has been out for over a month with Achilles tendonitis.
"He's doing great. Last week he started to train with us, so he's getting the feeling back little by little," said Simeone.
"We need him and expect the best of him. He's an important player for the team so I hope he can be the best version of himself against Malaga."
Simeone also responded to criticism from Fernando Torres' agent Antonio Sanz, who branded Atleti's style of play boring and claimed the Argentine should be let go.
"I'm very respectful with everybody's opinion and I always think that we can do better," he commented.
"I hope every opinion helps us to improve. I respect Antonio because I know him very well, and I know a lot of things about him, so I understand his tactics."