Simeone says Atletico 'lacked vision' in defeat at Leverkusen
Robert Andrich and Moussa Diaby scored late goals as Leverkusen moved second in Group B on three points, level with third-placed Atletico.
"We lacked that vision of the game that is needed to better choose that last pass to take the team mate to goal," Simeone told reporters.
"We had a very clear one with (Alvaro) Morata in the centre, another with Saul from outside, Joao (Felix) when he started taking the ball on the inside and had people on the right as well. Moves that obviously give the possibility to win the game."
Simeone said the team were caught out after pushing hard for the win.
"I think we were improving with the changes because the team was more dynamic in the game and had more speed to be able to attack," he said.
"But, sometimes it happens when you attack, there are times when you don't defend well and this time, possibly looking at winning it, we ended losing it as we would have liked to win it."
Atletico host Real Madrid in LaLiga on Sunday.