The Brazilian forward was suspended for Atletico's last two games, against Rayo Vallecano in La Liga and Rubin Kazan in the Europa League, both of which ended in defeat, but he will be back in the starting line-up on Sunday as Los Rojiblancos look for their first away win in the league since November.
"It's possible the team have missed him recently," Simeone said.
"His physical strength, his positioning in attack, his aggression and and his will to win make him a player that opponents really fear, and make him an important weapon for us.
"We hope he'll play well tomorrow [Sunday] and will be able to put in a good performance."
Atletico have won just two of their last six games in all competitions, but Simeone does not think their recent slump in form is anything to be concerned about.
"I still think the same about our objective, which is to keep playing each game as if it were our last, he said.
"That is what has made us one of the best teams so far this season. Of course, teams always have their better moments and others that are not so good, but assessments have to be made at the end of the season.
"We know that the important thing is how you finish and not how you are doing at a certain moment."
Simeone described Valladolid as "one of the stand out teams this season" and said his side would need to be more decisive in front of goal than on recent away trips if they are to come away with the three points.
Valladolid coach Miroslav Djukic insisted that, despite their recent poor run of results, Atletico were still a team that have achieved "extraordinary things" this season.
He said: "They are still second in the table, they are still involved in the Copa del Rey and they still have a chance in the Europa League - many teams would like to be in their position."
However, the Serbian coach admitted his team would try and take advantage of the fact that Simeone's might be tired following the defeat to Rubin Kazan on Thursday.
"We know they're going into the game having played last Sunday and then on Thursday, so we need to play with a lot of intensity," he said.