The Spaniard reportedly refused to train on Thursday, but the Los Colchoneros boss says the issue has already been sorted out internally
Diego Simeone revealed a disciplinary issue with Atletico Madrid striker Diego Costa has been settled before backing him to bounce back from a frustrating campaign.
Costa reportedly refused to train on Thursday over a club disciplinary process following his red card against Barcelona.
An outburst at the referee against La Liga's leaders earlier this month saw Costa sent off, then hit with an eight-match ban.
Atletico's slim La Liga title hopes were effectively ended as a result, but Simeone continued to defend the striker ahead of Saturday's trip to Eibar.
"What I can tell you is it's an internal situation, that we solved it yesterday and today Diego was training as he has always trained," Simeone told a news conference on Friday.
"I have explained several times. I do not change what I think about Diego. I think he did not have a good season, marked by injuries. And I have no doubt that next season, all the rebellion and all the players who is in all situations that have lived this season, will do very well.
"This season he has not been able to have continuity. Then the expulsion moves him away from the competition from here to the end and all this will make him a rebel. Costa will have a hunger and desire to reverse this situation that he has lived this season.
"Players today cannot take anything for granted in the future. Always the players can have the opportunity to leave. We always want to compete with the best and those that we consider that can make the team good and keep it growing."
Asked again about Costa's punishment over the ban, Simeone added: "I was clear at the start. It is an internal issue and has been resolved internally and is now resolved.
"It is an internal issue and we resolve it internally. In the family when situations happen they are resolved without telling anyone on the street."
Atleti can boost their chances of finishing second, above city rivals Real Madrid, by winning away to Eibar on Saturday.
"It will be a hard game like all against Eibar," Simeone said. "They are the one who presses in the best way among the rivals in Spanish football.
"Drowning the exit and trying to make mistakes. We know about their characteristics and will try especially at home to do it in the best way."
Diego Godin and Thomas Lemar are available after being given medical discharge from thigh and hamstring injuries respectively.