The capital outfit currently top the table on 88 points, four points ahead of second-place Barcelona and six ahead of third-place Real Madrid, who have a game in hand.
However, despite the gap, Simeone has called on his team to continue their winning run.
"We have two big rivals behind us and we simply cannot afford to lose," he told Marca. "This was an important win. We showed a great attitude and we fought nobly to get the three points. Valencia were very intense but I imagined they would be.
"I knew we were going to have a very tough first 30 minutes and every game at this stage of the season is complicated and requires a lot of effort."
Two wins from their final three league games would secure Atletico the title.