Atletico Madrid striker Diego Costa has returned from injury and is available for Tuesday's Champions League match against Liverpool.
Costa, who won the Premier League with Chelsea during a three-year spell, trained with his team-mates on Monday after recovering from surgery to correct a slipped disc in his back in November last year.
Speaking at his pre-match news conference Simeone confirmed Costa's availability for the first leg.
"He is improving. He is training with a lot of enthusiasm and he is in the group of 19 players that are in contention for tomorrow," Costa said.
Atletico could also be boosted by the return of Uruguay defender Jose Gimenez, who was on the bench for Friday's 2-2 draw with Valencia, for the match at the Wanda Metropolitano Stadium in Madrid.
However, two of the club's summer signings, Joao Felix and Kieran Trippier, are set to miss out for Atletico.
Felix, who was signed from Benfica for a club-record fee of £113m, has been struggling with injury in recent weeks, missing Atletico's last three matches.
Meanwhile, former Tottenham right-back Kieran Trippier has not featured for Atletico since last month's Spanish Super Cup final defeat to Real Madrid after undergoing surgery on his groin at the beginning of February.
Simeone: I admire this Liverpool side
Atletico have won one of their last seven matches which has seen them slip to fourth in La Liga, 13 points adrift of leaders Real Madrid.
Meanwhile, reigning Champions League holders Liverpool remain unbeaten in the Premier League and on course to win their first top-flight title since 1990, with Simeone full of respect for some of the shared traits between the two sides.
"I remember Klopp's Borussia Dortmund. [Liverpool] is a similar team in this respect," said Simeone, who has led Atletico to two Champions League finals.
"From that point of view of competitiveness and intensity we could say we are similar.
"These teams show our characteristics as coaches but of course the potential that different footballers have make teams play in a different way of course.
"We have always spoken about great teams throughout time and this Liverpool team is going to go down in history as a great team.
"They are different to other teams that we have admired. This team is much more intense, adaptable and it makes me admire it as a rival."