Beating Huesca secured a third successive victory for Atletico across all competitions, meaning they go to the Santiago Bernabeu in good form after beginning the season rather shakily.
Losing Gimenez – who has started four times in LaLiga this term – would be a blow to their chances, but Simeone is optimistic about his chances of featuring.
"We will see him tomorrow [Wednesday], but we have positive feelings that he will be fine for Saturday's derby," he said.
Atletico won just one of their first five matches – in 90 minutes – of the season across all fronts, but they are now starting to pick up form.
And Simeone is feeling confident heading to the Bernabeu for the first league derby of the season.
"We are growing in the associative game, we press more together," he said. "Against Eibar we already showed improvement, then better against Monaco and even better again against Getafe. This first time was strong and I hope that Saturday is like that.
"We arrive [at the derby] with good results. We hope to manage the days left with the right efforts to get there."
Simeone also applauded Atletico's supporters for their reception of Huesca coach Leo Franco, who played as a goalkeeper for the club for five years, one alongside his Argentinian compatriot.
"I wish him well," Simeone said. "It was nice that the fans remembered his time at the club.
"Hopefully, Huesca will move forward, transmitting everything he has learned in those years."