Simeone's men lost both legs of their Copa del Rey semi-final to arch rivals Real Madrid, those two games sandwiching a surprise 2-0 reverse at La Liga strugglers Almeria.
That defeat means they now sit third in the table, although they are behind Barcelona and Real, placed top and second, on goal difference only.
On Saturday, Atletico face a relegation-threatened Valladolid side that has won just four top-flight times this season, and Simeone says it is a good opportunity for his team to return to form.
"In principal, they're a good opponent to get back to winning ways against," he said.
"We've lost an important tie, without a doubt, and a game in La Liga. Now it is crucial to see how we can beat an opponent that comes here with a lot of motivation and with a lot of speed in attack.
"With us coming into this game having lost at Almeria, in football, we're invited to think that different things can happen."
With a UEFA Champions League tie with Milan looming, Simeone insists his side are taking things one game at a time.
"The truth is, I'm not thinking of Milan or the Champions League," he added.
"La Liga is very important, we want to have a good game and push ourselves ahead. At this time we're focused on Real Valladolid, because we need to have a good game."
Top scorer Diego Costa has hit a relative dry spell of late, with just one goal in his last five Liga matches, but Simeone said that was a due mainly to strong displays from their opposition.
"Opponents have been marking him well," the Argentinian continued.
"That's to the merit of the opposing defences and in neither of the last two games did he have scoring chances.
"We have to work hard to make sure the team can present him with clearer chances on goal."
