The midfielder was unplayable as Simeone's side won their second Primera Division games from as many attempts, as they continue to show they can perform without Radamel Falcao.
The Colombian's goals will be missed, but Simeone is pleased to see others, such as Garcia, filling the void.
"It makes me happy that Raul had such a good performance and scored two goals," the Argentinean said.
"We need people to interpret that we are a group first and then we will be a team. We wanted to find a good second ball and having Raul on the field allows us to play a better passing game."
With Atleti holding Barcelona to a 1-1 draw in the Supercopa last week, their start to the season looks all the more credible.
"We knew we could hurt them with a passing game and breaking from behind," Simeone said of the win over Vallecano.
"We played with a very high pressure for much of the game. We were able to steal the ball to hurt them and that was what we wanted to do."