Simeone could only watch on as his side let a golden opportunity to claim their first championship since 1996 slip against Malaga on Sunday.
Despite being on top throughout, Simeone's men could only manage a 1-1 draw at home as Toby Alderweireld's first league goal cancelled out Samu's strike.
Adrian Lopez's last-gasp effort being brilliantly tipped over by Willy Caballero summed up a frustrating day for Atletico, who could not capitalise on Barcelona being held to a goalless draw by Elche.
The upshot is that Barcelona and Atletico's meeting in the season finale now becomes a title decider at Camp Nou, with the hosts requiring victory to snatch the crown.
It is too close to call in the eyes of Simeone, who said: "It’s annoying when you give everything the game demands, because the players gave everything. Now there’s a 50-50 chance, just like in every final."
Simeone is well aware of the importance of the next week as Atletico attempt to complete a stunning triumph that few predicted before the start of the campaign.
"The history of Atletico is eternal," he added. "Sunday is vital day for the club. It’s not easy to stand back from reality and the rivals we are facing are used to these situations.
"We're humble and what this team has done is truly amazing. It's taken a lot of effort and I hope we can finish it off in the Camp Nou."
Atletico's cause would be boosted significantly if they could call upon Diego Costa, who missed out against Malaga due to a muscle problem.
Simeone kept his cards close to his chest on the star striker's recovery, saying: "He’s progressing well. We'll see how he is for the match."
