Simeone's side moved a point clear at the top of the table on Wednesday with a 1-0 victory over Granada, with Barcelona also taking maximum points against Celta Vigo.
Real, however, were beaten 2-1 at Sevilla as their El Clasico defeat on Sunday was compounded with a second straight league loss.
Despite boasting a narrow lead going into the final eight games, Simeone believes Real and Barca will bounce back in their bid for the crown.
"Madrid and Barca will fight until the very end. There are a lot of arguments in their favour," he said.
"We look at our work and I always tell the players that we depend on ourselves.
"That's how it’ll be until the end of the season, whether it goes good or bad."
The next instalment of Atletico's challenge for a first crown since 1996 comes with a visit to fourth-placed Athletic Bilbao on Saturday.
