Wednesday night's 4-2 win at Real Betis moved Atletico into second place, two points behind Barcelona, and extended their run without defeat to 16 competitive matches.
Simeone said: "We are improving all the time and I have no fear the team is going to suffer from vertigo.
"We do not look beyond the next game that is in front of us. It is logical that people are interested all the euphoria, but we will continue to look ahead without changing anything."
Espanyol in contrast are struggling at the wrong end of the table having taken a single point from their first five games - a 3-3 draw against Athletic Bilbao in which they blew a 2-0 half-time lead.
But Espanyol's Portuguese midfielder Diego Simao believes his side have shown enough good form this season to make any talk of crisis premature.
Simao said: "I would be worried if we lost and we had not been in the game, but we're doing really well - we have a good team and we are creating opportunities.
"We must stay calm and patient from the beginning to the 90th minute. We must have inner strength, and we must be united because if we are together it is much easier."