Atleti sit fourth after 12 games, winning five and drawing six with one defeat, heading into Sunday's meeting with Espanyol - who beat Ludogorets 6-0 in Europe on Thursday but have lost their last two league matches.
Los Rojiblancos are just two points behind current leaders Real Sociedad, though could have - temporarily at least - moved top themselves last week had they overcome Sevilla.
A defeat to Bayer Leverkusen in Wednesday's Champions League encounter means Atleti are now without a win in their last three matches in all competitions, and Simeone acknowledged his side - who have been hit by injuries to Jose Gimenez, Stefan Savic and Joao Felix - must regain the consistency which has made them regular title contenders in recent seasons.
"We keep thinking about the match. On Saturday, we play against an opponent with an important motivation with the new coach and it will be a complex match," Simeone told a news conference when asked if Atleti could challenge their city rivals and Barca.
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"It is complex. We have three important players injured, Joao Felix, Savic and Gimenez. When they are all fit we have more strength and competition. We need to convince ourselves of what we can do and from that find the consistency, which is what we are looking for.
"There are good passages, other bad ones and we need to work on concentration. That is what you get on the field, not from words. It is given by training and matches.
"We want to keep improving and our thinking does not go beyond the match against Espanyol."